Add way of handling optional mods

[EliSauder]

Currently there is no automatically way with the installer to handle optional mods (that I can find in the help options). There should be an interactive (select the optional mods you want installed) and an automatic (command line options that disable all, enable all, or enable select mods) way of managing optional mods upon installation.

[nothub]

Yeah I like this idea.

[nothub]

Working-branch: feature/optional-mods

[nothub]

Currently, all optional mods will be installed.
The same behavior should be the default behavior when this feature is implemented.

New flags:

• --optional-select=<modid>,<modid>,<modid>
• --optional-disable-all

[nothub]

Hmm, I just realized that no reference to the mod-id is included in the modrinth.index.json file itself.

The mod would have to be downloaded and the included modloader-specific metadata read to obtain the mod-id. So instead of using the mod-id for the --optional-select flag, it is probably better to use some kind of name pattern.

[nothub]

I did not add an interactive dialog yet, this might be added in a later version.