FINERACT-2832: Migrate groups and centers to CommandDispatcher

[avivijay19]

Description

Moves the write side of GroupsApiResource and CentersApiResource to the typed CommandDispatcher (same pattern as FINERACT-2288 Staff and the Meetings/Notes migrations): one request DTO, Command and CommandHandler per action, typed services (GroupingTypesWriteService, GroupRolesWriteService), programmatic Jakarta validation, and per-command authorization in SecurityConfig through a query-parameter-aware request matcher for the ?command= endpoints (existing ACTIVATE_GROUP, ASSOCIATECLIENTS_GROUP, … authorities). The bulk-import handlers dispatch typed requests; the client-transfer and collection-sheet services each gain one typed adapter method (transferClientsBetweenGroups(request), saveGroupCollectionSheet(request)), other callers untouched. The legacy path — the 22 @CommandType handlers (including TransferClientsBetweenGroupsCommandHandler) plus the unreferenced UnassignStaffFromCenterCommandHandler, the Gson validators, GroupingTypesWritePlatformService, GroupRolesWritePlatformService, the CommandWrapperBuilder group/center builders and the hand-written GroupsApiResourceSwagger / CentersApiResourceSwagger stubs — is removed.

Request and write-response schemas are now generated from the real classes, and the read schemas reference the real DTOs (GroupGeneralData, CenterData, GroupsPageResponse, CentersPageResponse, AccountSummaryCollectionData) instead of the stubs — this closes the gaps reported in FINERACT-2832 (accountNo on the list items; staffId, centerId, clientMembers, datatables on the create request) by construction. The read endpoints themselves are unchanged: they keep the existing JSON serializer, ?fields= support and date format; their READ_GROUP / READ_CENTER check moves from the resource into SecurityConfig, scoped to the routes these two resources serve.

Wire contract: same URLs, methods, query parameters and ?command= values, same field names, dates, validation rules and error-body shape. Verified with the existing integration suites (GroupTest, CenterIntegrationTest, LoanReschedulingWithinCenterTest, GroupSavingsIntegrationTest, GroupLoanIntegrationTest, MakercheckerTest, AccountNumberPreferencesTest) and by exercising every write endpoint and ?command= value over HTTP, including the roles, client-transfer, collection-sheet and bulk-import paths, which have no integration suite.

Deliberate differences, consistent with the other CommandDispatcher migrations:

• maker-checker no longer applies to *_GROUP / *_CENTER tasks, and the legacy webhook events for GROUP / CENTER no longer fire;
• audit is written to m_command instead of m_portfolio_command_source;
• unknown keys in a request body are ignored instead of rejected with 400;
• validation errors keep the {"errors":[{parameterName,…}]} shape but carry the constraint's org.apache.fineract.portfolio.group.<parameter>.<rule> globalisation codes instead of validation.msg.group.<parameter>.…; the unsupported-?command= error lists the real command values (the legacy list was incomplete and contained the typo updateassignRole);
• PUT /groups/{id} and PUT /centers/{id} with an explicit "staffId": null / "centerId": null no longer unassign — use ?command=unassignStaff / disassociateGroups as before;
• DELETE /groups/{id} and ?command=unassignStaff previously returned officeId and groupId swapped; they now carry the correct values;
• POST /groups accepts centerId without officeId (the office is taken from the centre), matching what the service always did;
• ?command=transferClients rejects an empty clients list with 400 (legacy silently did nothing);
• ?command=generateCollectionSheet now requires READ_GROUP / READ_CENTER (legacy checked authentication only);
• OpenAPI schema names change (PostGroupsRequest → GroupCreateRequest, GetGroupsGroupIdResponse → GroupGeneralData, …), so the api-compatibility check reports renames.

Authorization hardening for these two resources: the matchers accept a ?command= value with surrounding whitespace and a trailing slash on the path, exactly as the resource and Jersey do, so a request cannot reach the handler without passing the matcher. Note for follow-up: the matchers of the already-migrated Staff/Meetings/Notes resources do not tolerate a trailing slash while Jersey does; that is outside this ticket.

Also worth knowing: a ?command= request with no body now gets a 400 (the typed request must be present; send {} for unassignRole / unassignStaff), where the legacy resource tolerated an empty body; and a missing roleId on updateRole / unassignRole still 500s exactly as on develop.

Observed while testing, not changed here: ?command=generateCollectionSheet on both /groups/{id} and /centers/{id} fails on PostgreSQL with operator does not exist: boolean = integer (CollectionSheetReadPlatformServiceImpl), on develop as well.

Checklist

• Write the commit message as described in https://github.com/apache/fineract/#pull-requests
• Acknowledge that we will not review PRs that are not passing the build
• Create/update unit or integration tests
• Follow coding conventions
• Add required Swagger annotation and update API documentation
• Submission is not a "code dump"
• Run the full CI locally