feat: Mechanism to upgrade to packages

[GeckoEidechse]

We need some way for user to change their setup to packages I'm too time limited to get a proper UI and everything so I propose we hijack our existing update prompt for mods to achieve this.

Simply put:

• Give an outdated version number on legacy installed Thunderstore mods (I'm using 0.0.0 for this which is not available on Thunderstore)
• User has the option to "update mod"
• Adjust our update mechanism so that it also removes legacy versions of installed mods on successful update.

TODO:

• Spoof version number
• Remove legacy install on successful update ( feat: Support installing Thunderstore packages #426 )

Part of #415

[GeckoEidechse]

There might be a better mechanism to do this, other than pretending mod is outdated.

Also I'm pretty sure having multiple mods outdated and spam clicking them to update causes some issues (at least based on past experience where install would then fail sometimes). So if we go with this approach we might wanna have an "update all" option or a way to block installing/updating another mod while current one is being installed.

[Alystrasz]

Give an outdated version number on legacy installed Thunderstore mods (I'm using 0.0.0 for this which is not available on Thunderstore)

If it works, it ain't stupid, right?

or a way to block installing/updating another mod while current one is being installed.

Another issue for another day 😄