Hud config framework

[MjnMixael]

This PR relies on #6487 and #6481 . It sets up the necessary framework to be able to render each HUD gauge in "config" mode which will allow rendering the gauges outside of a mission environment, namely the HUD Config screen. For now the config argument is commented out because it's unused. The bulk of the changes here are in hud.cpp and the various rendering methods where in config mode we don't do any screen resizing.

Config mode requests to render each gauge not only scaled down slightly but at an arbitrary offset depending on whether we're rendering through the retail UI or SCPUI. For that reason I found it was much easier to calculate a gauge's position and scale manually within the gauge render code itself where we also have access to the bitmap with it's height and width. This also allows us to save those coordinates to an array to use against the mouse coords to detect mouseover and click on these rendered gauges. The relevant code, shown below, is currently unreachable since nothing calls them. HC_gauge_coordinates is never initialized for now. That will be resolved in the big HUD Config UI overhaul PR.

Future PRs will systematically go through each gauge rendering code and build out the full config mode rendering path which mostly consists of setting the coords, scale, and providing dummy data where mission data is currently expected.

void hud_config_convert_coords(int x, int y, float scale, int& outX, int& outY)
{
	outX = HC_gauge_coordinates[0] + static_cast<int>(x * scale);
	outY = HC_gauge_coordinates[2] + static_cast<int>(y * scale);
}

void hud_config_get_scale(int baseW, int baseH, float& outScale)
{
	// Determine the scaling factor
	float scaleX = static_cast<float>(HC_gauge_coordinates[4]) / baseW;
	float scaleY = static_cast<float>(HC_gauge_coordinates[5]) / baseH;

	// Use the smallest scale factor
	outScale = std::min(scaleX, scaleY);
}

void hud_config_convert_coord_sys(int x, int y, int baseW, int baseH, int& outX, int& outY, float& outScale)
{
	hud_config_get_scale(baseW, baseH, outScale);
	hud_config_convert_coords(x, y, outScale, outX, outY);
}

void hud_config_set_mouse_coords(int gauge_config, int x1, int x2, int y1, int y2) {
	HC_gauge_mouse_coords[gauge_config] = {x1, x2, y1, y2};
}

[wookieejedi]

Tagging as 25.0 for now since it is foundational for the HUD configure updates, which will be extremely useful for all mods.

Discussing with MJN, he calculated the best order of operations for the process is as follows:

1 Font scaling PR: #6481 (and #6330 and #6342, which are both done)
2 Bitmap scaling PR: #6487
3 Hud Config framework PR (this PR)
4 Individual gauge changes (Upcoming: probably multiple PRs that can go simultaneously)
5 Hud config UI overhaul (Upcoming)