Update guided installer abstraction and FOMOD installer

[erri120]

Followup on #532 and part 2 of #316. Blocked by #540 and #542.

Fixes #544.

Changes:

• Complete rework of IOptionSelector. We now have the IGuidedInstaller interface and more internal types that aren't directly related to FOMODs.
• The CLI installer received massive changes and needs to be tested before merging.
• Contains a new project NexusMods.Games.FOMOD.UI that isn't complete yet, but will be worked on in the next PR.

Originally, I wanted to implement the required ViewModels for the FOMOD UI. However, I had to rework some of our existing FOMOD code because the API of the library we're using is pretty bad.

[github-actions]

This PR conflicts with main. You need to rebase the PR before it can be merged.

[github-actions]

This PR doesn't conflict with main anymore. It can be merged after all status checks have passed and it has been reviewed.

[Al12rs]

I tested installing a mod from CLI locally, and I found that the experience was rather confusing.

Would it be possible to print a description of the expected operation that the user needs to take depending on the type of option group? (ExactlyOne, AtMostOne, AtLeastOne, Any)

Like: "Select at least one of the following options"

[erri120]

I tested installing a mod from CLI locally, and I found that the experience was rather confusing.

Would it be possible to print a description of the expected operation that the user needs to take depending on the type of option group? (ExactlyOne, AtMostOne, AtLeastOne, Any)

Like: "Select at least one of the following options"

The CLI shouldn't be different from main. I did change the internal logic and adapted the code to the new system, but the presentation and usage should be the same.

[Al12rs]

Also the installer shows "Back" instead of "Next" I think:

[erri120]

Also the installer shows "Back" instead of "Next" I think:

Always has been

NexusMods.App/src/NexusMods.CLI/CliOptionSelector.cs

Lines 12 to 16 in 1a21c5d

	private const string ReturnInput = "x";
	private static readonly string[] TableOfOptionsHeaders = { "Key", "State", "Name", "Description" };
	private static readonly object[] TableOfOptionsFooter = { ReturnInput, "", "Back", "" };
	private static readonly string[] TableOfGroupsHeaders = { "Key", "Group" };
	private static readonly object[] TableOfGroupsFooter = { ReturnInput, "Continue" };

[github-actions]

This PR conflicts with main. You need to rebase the PR before it can be merged.

[github-actions]

This PR doesn't conflict with main anymore. It can be merged after all status checks have passed and it has been reviewed.