Due to `utils` module removal, `EXTERNAL_CONFIG_FLAGS` was not working, so the system was redesigned.
This change is independent of #4411

Examining the code shows that the rectangle is drawn winding counterclockwise, starting
with the top left. Therefore the colors used should be in the order: topLeft, bottomLeft,
bottomRight, topRight.

However, the variables actually being used are topLeft, bottomLeft, topRight,
bottomRight. I was confused by this as I was getting striping where I didn't expect any.
Put another way, the last two parameters are misnamed.

This diff swaps the parameter names and their usages. The result is that no runtime
behaviour changes: the same parameter order yields the same visual result both before and
after this change, but the parameter names now correctly reflect what they are actually
used for.

You can actually see this in the implementation of DrawRectangleGradientV, which
(correctly) passes top, bottom, bottom, top to DrawRectangleGradientEx.

Prevents unnecessary work and division by zero (when segments=0) in DrawCircleSector/DrawCircleSectorLines when startAngle equals endAngle, matching existing behavior in DrawRing/DrawRingLines.

Closes #4673

* fix pixel offset issue with `DrawRectangleRoundedLinesEx`

* improve fix - (pixel offset issue with `DrawRectangleRoundedLinesEx`)

* revert radius tweak (`DrawRectangleRoundedLines`)

* [rshapes] Remove `DrawRectangleLines()`'s + 1 offset

* ... and replace it with a -/+ 0.5 offset divided by current cam's zoom.

void DrawCircleGradient(int centerX, int centerY, float radius, Color color1, Color color2);
void DrawRectangleGradientV(int posX, int posY, int width, int height, Color color1, Color color2);
void DrawRectangleGradientH(int posX, int posY, int width, int height, Color color1, Color color2);
void DrawRectangleGradientEx(Rectangle rec, Color col1, Color col2, Color col3, Color col4);

Have been changed to:

void DrawCircleGradient(int centerX, int centerY, float radius, Color inner, Color outer);
void DrawRectangleGradientV(int posX, int posY, int width, int height, Color top, Color bottom);
void DrawRectangleGradientH(int posX, int posY, int width, int height, Color left, Color right);
void DrawRectangleGradientEx(Rectangle rec, Color topLeft, Color bottomLeft, Color topRight, Color bottomRight);

* Change some global variables to have internal linkage

* Update rcore.c

* Update rcore.c

* remove function call

* fix

* [rshapes] Fix multisegment Bezier splines.

It seems to me that these functions are wrong, if you step the index by 1 you move to a control point instead of the next segment.

* Fix example shapes/shapes_splines_drawing for bezier splines.

* Draw circles to fill gaps between bezier segments.

* Update raylib_api.* by CI

* make functions that take a pointer to an array take them as const pointers

* Update raylib_api.* by CI

* fix comment alignment.

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

* inital function

* working 1

* optimize

* optimized dot product

* simplify

* cleanup

* cleanup

* cleanup

* comment

* var name change

* epsilon

This could be actually very tricky and GPU/drivers dependant...

For consistency, now _almost_ all `Draw*Lines()` functions use `RL_LINES` mode for drawing. It solves the linked issue but it can have other implications, as mentioned in the WARNING comment in `DrawRectangleLines()`.

Side note: `DrawRectangleRoundedLines()` now should be reviewed for consistency.

- Review formatting
 - Improve readability for some functions result return
 - Minimize early returns
 - Align LoadFileData() to UnloadFileData()

* provide access to the shape texture so that shapes can be extended outside of raylib with the same optimizations as internal raylib functions.

* PR feedback, comply with C standards

* oops