feat: allow timeout-related commands to be used in multiple channels (#5402)

This changes the behaviour of the following commands:
 - `/ban`
 - `/timeout`
 - `/untimeout`
 - `/unban`

All of those commands now accept one or more `--channel` parameters to override which channel the action should take place in.
The `--channel` parameter accepts a channel ID or channel name with the same syntax as the other "user targets" do (e.g. `id:11148817` or `pajlada`)

examples
Ban user in the chat you're typing in:  
`/ban weeb123`

Ban user in the chat you're typing in, with a reason specified:  
`/ban weeb123 the ban reason`

Ban user in a separate chat, with a reason specified:  
`/ban --channel pajlada weeb123 the ban reason`

Ban user in two separate chats, with a reason specified:  
`/ban --channel pajlada --channel id:117166826 weeb123 the ban reason`


Timeout user in the chat you're typing in:  
`/timeout weeb123`

Timeout user in the chat you're typing in, with a reason specified:  
`/timeout weeb123 10m the timeout reason`

Timeout user in a separate chat, with a reason specified:  
`/timeout --channel pajlada weeb123 10m the timeout reason`

Timeout user in two separate chats, with a reason specified:  
`/timeout --channel pajlada --channel id:117166826 weeb123 10m the timeout reason`


Unban user in the chat you're typing in:  
`/unban weeb123`

Unban user in a separate chat:  
`/unban --channel pajlada weeb123`

Unban user in two separate chats:  
`/unban --channel pajlada --channel id:117166826 weeb123`

tests/CMakeLists.txt

@@ -44,6 +44,7 @@ set(test_SOURCES
     ${CMAKE_CURRENT_LIST_DIR}/src/QMagicEnum.cpp
     ${CMAKE_CURRENT_LIST_DIR}/src/ModerationAction.cpp
     ${CMAKE_CURRENT_LIST_DIR}/src/Scrollbar.cpp
+    ${CMAKE_CURRENT_LIST_DIR}/src/Commands.cpp
     # Add your new file above this line!
     )