Separate modlist.txt/plugin.txt from graphics preset

[MattLish]

From the user's perspective, they need to just be able to change graphics settings and shader settings.

If we had 2 profiles, one for potato and one standard one, along with a launcher/graphics_presets directory that contained the different presets files.
When a user selects a graphics preset, the launcher copies into both the potato and standard profile (along with any other custom ones in there).

Users can select graphics and you only have to maintain the 2 modlists.

The launcher may still need to support the old version for users that have not yet updated.
Or, release it as 3.0.0 and prevent 2.0.0. from updating.

The full discussion is in the private Discord for more information https://discord.com/channels/344256550640287755/1009496394148630548

• Selection copies to profiles
• Restore. (Restoring profiles or graphics needs to copy graphics into profiles again).
• Migrate old installs to the new style.
• Combine into Standard modlist and Performane modlist
• Ensure any profiles that do not match the backup are not touched.

Test cases

• Fresh install - No settings
• Fresh install - Previous settings with valid profile
• Fresh install - Previous settings invalid profile
• Fresh install - Previous settings with noEnb
• Fresh install - Previous settings with ultrawide
• Existing install - Previous settings with valid profile
• Existing install - Previous settings invalid profile
• Existing install - Previous settings with noEnb
• Existing install - Previous settings with ultrawide
• Existing install - Previous settings with valid profile and genuine modified modlist
• Existing install - Previous settings with invalid profile and genuine modified modlist
• Existing install - Previous settings with noEnb and genuine modified profile
• Existing install - Previous settings with ultrawide and genuine modified profile
• Existing install - previous settings with edited INI files

[MattLish]

If the modpack does not support separated graphics settings, the launcher can first transform it to match the new standard

[MattLish]

Migration notes:

• If a user has a Graphics Presets already, do not migrate.
• If not, move Skyrim.ini/SkyrimCustom.ini/SkyrimPrefs.ini to a directory with the same name in launcher/Graphics Presets. Ensure backup happens after.
• If the modlist/plugins/loadorder matches the backup, combine into a potato modlist and standard modlist profile.
• If the modlist does not match, just copy into a profile with the same name