Allow syncing of just one file or selection of files/bundles via materialise

[HarryCampion]

[tschm]

@HarryCampion Feels like an odd function to me...

[HarryCampion]

sometimes I want to sync a file that' not in the template just to bring it in to then edit it directly as sync will override

[HarryCampion]

the new sync sort of makes this obsolete unless there is a merge conflict