update: add Vector2.hpp based on old vector3 functions

[Hugo-Cathelain]

Closes #{LINK TO GITHUB ISSUE}

Type of Change

• 🐞 Bug Fix (non-breaking change which fixes an issue)
• ✨ New Feature (non-breaking change which adds functionality)
• 💥 Breaking Change (fix or feature that would cause existing functionality to not work as expected)
• 🧹 Refactor (code cleanup, architectural improvement, or progressive abstraction)
• 📖 Documentation Update
• 🧪 Tests / CI / Build System (CMake) Update

Description

Adding old Vector2 that wasn't pushed at the time and were sitting on another machine

Docs

like old vector3 docs and will need change ^^

Checklist

• My code follows the gp-engine C++ Coding Standard.
• I have compiled the engine successfully using the modern C++23 toolchain (GCC 13+, Clang 16+, or MSVC 19.38+) and CMake.
• I have performed a self-review of my code and added comments, especially in complex areas like shader programming or math-heavy algorithms.
• I have updated the relevant API reference or learning path documentation (if applicable).
• My changes generate no new compiler warnings in the build log.
• I have read and agree to the Code of Conduct and Contributing Guidelines.

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[github-actions]

Welcome to Graphical Playground (gp-engine), @Hugo-Cathelain! 🎉

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[mallory-scotton]

Overall LGTM, but please review the small nitpicks I commented

[mallory-scotton]

The code hasn't be formatted using clang-format, otherwise, this spaces wouldn't been there, please format the code !

[mallory-scotton]

Please use the invScale to gain a bit of performance per CPU cycle

[mallory-scotton]

Suggested change

	GP_ASSERT(scale != T(0), "Division by zero");
	GP_ASSERT(scale != T{ 0 }, "Division by zero");