show a user friendly description of the starting unit template

closes #6209
beautify starting unit notification when joining server

move LobbySettingsNotification into it's own ServerTrait
Merge pull request #6217 from Mailaender/starting-units-classname

Fixed lobby start unit notifications not showing class names
Introduces ReloadModifier
and renames ROF -> ReloadDelay
ReloadModifier & ROF -> ReloadDelay yaml changes
Upgrade rule for ROF > ReloadDelay renaming.
Adds length display support for PCM & IMA music.
Merge pull request #6089 from reaperrr/wavlength

Add WavSoundLength to show track length in music player
Merge pull request #6079 from reaperrr/rof-modifier

Adds ReloadDelay modifier & renames ROF to ReloadDelay
Fixes year numbers in license text in file headers.
Merge pull request #6296 from mizipzor/fix-license

Fixes year numbers in license text in file headers.
Added a trait that removes an actor when prereqs are met, with delay.
Merge pull request #6109 from WolfGaming/RemoveOnPrereq

Added a trait that removes an actor when prereqs are met, with delay.
Added filter logic. Hardcoded for now, just to test the actual algorithm and server response to detect early issues.
Changed OpenRA.Game/Map/TileSet.cs terrainInfo to TerrainInfo and made it public

Added logic on change color command to take in consideration other player's colors and the current map's colors
Tweaked the threshold a bit, and fix the map and player color check.
Now validates new bots colors.
Refactored validation logic to be easier to reuse.
pending work...
Tweaks under color validations! Changed Delta function and polished code
Added color alternative function. Still not ready though.