Dev - remove deprecated text commands and convert commands running in hybrid mode

[suvanl]

This PR chiefly completely removes deprecated text commands and converts commands running in a so-called "hybrid mode" over to full Application Commands.

The deprecated (and now removed) commands are:

• ping
• user
• level

The commands running in hybrid mode which are now full Application Commands are:

• about
• server
• Spotify
• weather
• forecast
• avatar
• points

Other miscellaneous changes include:

• using the new user flag names (ad660963a5ad13382efaa130a4c5a420bdd024e8)
• switching to v10 of the Discord API in the deployApplicationCommand function (2bcd7f495b7ee7f2bf417435a75f07802e120764)
• moving the logger out of the "modules" folder and into the "util" folder (e50ead63f467ddee622b16cc8c53b806f56d5ab0)
• only including the date in the logger in production mode (7d4e5794aa84b1702171b76a4739bf80296ee492)

Documentation changes:

• update installation instructions to include Redis and delet3-api; clean up environment variables guide (dc89cae753d299e00d7b77099bbd95f5ee49f633)

[suvanl]

For the sake of clarity: "hybrid mode" was where a command would exist in both text command and application command format. The command implementation would exist in the text command's source file, while the application command would simply call the run() function from the text command. This was possible as the interaction object is very similar in nature to the message object.