[feat] command that shows mods/plugins with available updates

[Sandr-aa]

For example, having an mcman check-updates command, which either auto updates everything or prompts with an version selector like the one used when importing an modrinth mod over cli if an newer version has been released

[deniz-blue]

This will be added in v2, we'll also drop support for "latest" versions so using this mcman update command will be neccesary

[BANanaD3V]

we'll also drop support for "latest" versions

Yes, this will make mcman reproducible, although we should have a strategy for when a plugin version is unavailable (say, author deleted the specific version)

[deniz-blue]

i dont think theres anything we can do in that situation other than failing the build