Added Unit Attribute and Sample Usage

[Kinggrass]

This PR adds a new UnitAttribute to Tri-Inspector along with sample usage demonstrating various unit types.

Changes:
Added: Unit(Drawer/Attribute) class for rendering unit suffix in the inspector.
Added: Decorators_UnitSample scriptable object with various unit types.
Updated: README.md with example usage of the new Unit attribute.
Reorder: Various attribute files to better organize attributes into appropriate categorized folders.

Impact:
Enhances the inspector with unit display capabilities.
Provides examples for using units in different contexts.

Testing:
Verified the UnitDrawer renders correctly with different units.
Confirmed the example in README.md works as expected.

Preview:

    [Unit("My custom Unit")]
    public float freeTextUnit;

    [Unit(UnitAttribute.Meter)]
    public float lengthInMeters;

    [Unit(UnitAttribute.Centimeter)]
    public float lengthInCentimeters;

[retroluxfilm]

Great contribution. Hope to see a new version soon to use this feature. @vanifatovvlad