Replace hud_reloadscheme hack with EditablePanel + LoadControlSettings, indirectly fixes MOTD title + layout

[nullsystem]

• Both ammo and health-aux huds had a hack which forces hud_reloadscheme to be called on initialization. However this has visibly caused an issue with the MOTD which in Valve's code resets the data and look a bit odd. This also enforced reload on all huds which is unnecessary.
• The proper way to load those HudLayout.res settings is instead to have those inherit EditablePanel which most importantly provides a method LoadControlSettings to properly load those settings instead.
• This also refactor the font applying to ApplySchemeSettings
• Minor edit in HudLayout.res chat box is intentional otherwise there's a permanent background with using this EditablePanel change.
• fixes neo_hud health/compass/ammo need to change to EditablePanel #367

Testing

• What to change around:
  • Change/add around values in: scripts/HudLayout.res. Minimal example to differentiate from defaults. Compass +20 instead of +3, Ammo read bg, Health bar RGB, 255-0-255:

    NHudCompass
    {
            "fieldName"             "NHudCompass"
            "y_bottom_pos"          "20"
    }
    NHudWeapon
    {
            "fieldName"             "NHudWeapon"
            "box_color_r"           "254"
    }
    NHudHealth
    {
            "fieldName"             "NHudHealth"
            "health_color_g"        "0"
    }
    

• What needed to be checked:
  • First time loading in, make sure HudLayout.res setting is applied
  • hud_reloadscheme works as usual
  • N-times loading in, HudLayout.res setting is applied
  • Without PR Don't show MOTD by default, don't ever show for loopback #366 the MOTD retains its layout and server title. It doesn't display something in the central area but that's part of that PR's change. With PR Don't show MOTD by default, don't ever show for loopback #366 it should look functional.

[Rainyan]

So, the MOTD layout indeed seems fixed by this PR:

However, after using hud_reloadscheme, the layout is broken again upon next server join:

Is this MOTD business outside the scope of this PR?

[nullsystem]

@Rainyan Actually, only the server title/contents being intact being the main fix of this regarding MOTD. So I shouldn't really have mentioned the layout stuff. Technically though, the 2nd picture's "broken" layout is the "actual" res layout of the MOTD straight from OG:NT's TextWindow.res file I think. The fix is probably more like define our own one that doesn't look so bad/closer to HL2's one and also fix that vguitextwindow class to read from the res from the beginning.

So in this case, yeah out of scope of this PR.

[nullsystem]

@Rainyan Try out with the latest commit in, I think it's just moving around SetScreenSize/SetBounds lines caused it. Don't think I see the warning after the commit (but seen before) but have a check.