On the topic of self hosted .mrpack drawbacks

### Enhancement Type

Improve an existing feature

### Describe the enhancement

From what I've noticed (and it could me being blind), there seems to be no clean way of updating a modpack when providing a url to your self hosted .mrpack. I tried bumping the version but it didn't catch on. So far best solution I've found is to jump into the container and remove the existing .mrpack. Preferably the container would check for an existing .mrpack and compare versions and names, if the name+version don't match, redownload the mods.

Start by tracing the container startup logic that handles a self-hosted .mrpack URL and the existing local .mrpack. Check how the pack name and version are currently obtained and compared. Done means a changed name or version causes the updated pack and mods to be downloaded without manually removing the existing file.

Written by the indexing model from the issue text.