Improve Vec4Base sub-class functionality and Vec4 directional vector method name change

[rh101]

Describe your changes

Move methods from Vec4 to Vec4Base, specifically set(x,y,z,w) and set(float*). This allows their usage in Color4F and other sub-classes of Vec4Base.

Remove trivial copy constructor method, since it does not need to be explicitly implemented.

Rename Vec4::set(const Vec4& p1, const Vec4& p2) method to Vec4::setDirection to reflect its actual purpose.

If anyone currently uses the Vec4::set(const Vec4& p1, const Vec4& p2), then it is a simple rename to Vec4::setDirection(const Vec4& p1, const Vec4& p2). The set name was a bit misleading, and this change renames it to what the method actually does, which is to calculate the directional vector from point p1 to point p2. The compiler will throw an error regarding this, so there is no danger that this goes unnoticed.

Note that I did try to add the AX_DEPRECATED_ATTRIBUTE specifier to the the Vec4::set(const Vec4& p1, const Vec4& p2) method, but the compiler would throw errors when attempting to use the other set methods that were moved to Vec4Base, since they were being hidden by the Vec4::set method.

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[aismann]

@rh101
Is the title correct?
...Enhanced Color4F ...

[rh101]

Is the title correct?
...Enhanced Color4F ...

Fair point, as initially there was changes to the Color4F class, but they I reverted them before creating this PR, since they were not required. I'll fix the title to be more appropriate, since the enhancement to Color4F was more a side-effect of the change.