feat: bosshud

[notkoen]

Adds the BossHUD feature from CS:GO and CS:S, with many inspirations taken from the plugins by BotoX, CrazyKid, Shufen, AntiTeal, and tilgep for design. Majority of the core code was written by @tilgep, all credits goto her.

To-Do:

• Create a brand new particle for the public release since the original particle used was under GFL folder

ConVars:

• bosshud_enable - Whether to enable BossHud features
• bosshud_simplehud - Whether a simple BossHud is shown on maps without a config
• bosshud_scoreboard - Whether boss hits are displayed as assists on scoreboard
• bosshud_tophits - Whether top boss deamage is displayed after boss death
• bosshud_reward - Money rewarded to players per boss hit
• bosshud_hitmarker - Whether to enable hitmarkers for bosses
• bosshud_hitmarker_particle - The particle to use for boss hitmarker
• bosshud_rate - How often does BossHud update
• bosshud_maxhp - Bosses with more than this HP will not start showing on the HUD (0.0 = no limit)

Commands:

• !bosshud / !bhud - Toggle BossHUD modes
• !bhud_reload - (Re)loads the current map's BossHUD config
• !bhud_dump - Prints the currently loaded BossHUD config to console