[disma-cli] Add "add" command

[vigenere23]

Add add (or track) command to CLI for gradually tracking guild components.

Sucommands:

• role <name>: Track a role with name name. Should detect if duplicated names are present, and throw an error if so.
• category <name>: Track a category with name name. Should detect if duplicated names are present, and throw an error if so.
• channel <category_name:channel_name>: Track a channel with name channel_name in the category category_name. Should detect if duplicated names are present in the same category, and throw an error if so.
• all: Track everything. Equivalent to save. Should overwrite existant entries.
  • all {roles, categories, channels} : Track everything but only for the specified component. Should overwrite existant entries.