merge_into ignore when no changes

[sverbruggen]

In the merge_into method defined in lakeFS/clients/python-wrapper/lakefs /reference.py please add a parameter that will ignore the merge if there are no changes. As it is, the merge will fail with a bad request error.

[itaigilo]

Will be solved in a more general manner, by issue #7797.

[itaigilo]

The current state: In case of merging two branches with no changes, a no changes error will be thrown (and the branches won't be merged).

The change we're about to release: In case of merging two branches with no changes, it will still throw a no changes (and the branches won't be merged). And adding an allow_empty flag for this merge, will perform the merge (with no errors - and it'll create an empty commit for the merge).

@sverbruggen will this help for your case?

[sverbruggen]

@itaigilo yes that's great, thank you!