More helpful remote commit subjects

[cassidyjames]

Right now all the commit subjects are in the format Export com.github.cassidyjames.dippi which makes it difficult to identify which commit points to which version of the app, which is needed to install a specific version.

To reproduce

1. Run flatpak remote-info --log appcenter com.github.cassidyjames.dippi or the same command for any other app
2. Look at the subjects

Proposal

Add the app's version number to the commit subject.

[cassidyjames]

It's an argument to flat-manager-client which is ran by Bilal's GitHub action. Don't know whether it's exposed as a parameter to the action and I'm mobile so it's a pain to look if it is
–@davidmhewitt