add: ET protocol 84 and 284 (ETTV)

[ryzyk-krzysiek]

Hello,

Some time ago I've added ET protocol support 84 and 284 (ETTV also known as tv 84) but I don't think it's 100% finished or would be up to your standard (for example I've changed some stuff where according to your comments it is an issue (API stuff)). And so I thought about opening PR as draft only (if it's not an issue) in case maybe you/someone would be interested in it and finishing it (I don't think I will unless you have interest in looking into it and letting me know what I should do, but I can't promise I would do it anyway) or just using it.

What I added more specifically:

• added protocol 84 and 284 demo parsing
• added ET legacy mod constants, some overlap with other mods but not everything
• added ET configstring parsing (not 100% sure it behaves correctly I didn't do much testing here other than it works)
• added ET obituaries parsing, uses legacy mod meansofdeath which is a bit different for all other mods pretty much
• added ET scores parsing
• added ET ws parsing legacy/etpro/other
• added ET sc parsing legacy/etpro/other
• added ET chat parsing legacy/etpro/other
• protocol 284 parsing required some additional stuff for base parser as it differes a bit than all other protocols (and the logic might be a bit scuffed)
• added conversion from 284 protocol to 84 by cutting by time to a specific players PoV
• added to GUI a dropdown of possible conversions from 284 to 84 (dropdown shows the name of the player and times where it will be cut so if someone wants the cut to be more specific, first convert to 84 and then use other already existing features)
• as a note most etpro mod server commands are encoded and because as far I know they tried to reduce bandwidth they changed what fields have in them (at least for some, see obituaries parsing) compared to other mods
• changed some API stuff, like increased UDT_PLAYER_STATS_MASK_BYTE_COUNT from 40 to 50, also see this https://github.com/mightycow/uberdemotools/pull/2/files#diff-24ee4628e8f257ce90821ffd08be109419d57ecdb6e23cd87fb4b5ab92655326R72