Housekeeping: Delete old or stale branches, general branching rules

[dirkolbrich]

How about cleaning this repo up a little bit and delete stale and/or old branches which apparently do not serve any purpose anymore. Criteria would be branch is in the branch tree of an actual active branch or is merged into the current active branch (v0.8.0?) or any other older main branch. Maybe give the to be deleted branch a tag with its branch name before deletion.

Some of these branches to be deleted are (alphabetically order just for the first few finds):

• 0.8.0 - is part of the current v0.8.0 branch tree
• 5602-housekeeping-to-prep-for-infrastructure-authoring - part of the v0.8.0 branch tree and older than 1 year
• Assign_Product_In_Any_Order - part of the v0.7.0 branch tree, later merged into v0.8.0
• fix-missing-py39 - direct part of the current v0.8.0 branch tree
• hdf5 - part of the v0.6.0 branch tree, later merged into v0.8.0
  ... and so on

There are also a lot of dead-end branches, which seem to be experiments by the respective contributor but only have a few commits with no apparent result and are not merged into any of the main branches. These should be deleted too and live on in the contributors own repo.

• bim_select_aggregate_deselect_intial_object
• check_to_see_if_context_exists
• dynamic_font_size
• expose_identity_entity_map
• font_scale
  ... and so on

There should be some general ruling about branch hygiene. Do not create experimental branches for one-of shots in the main IFCOpenShell repo, keep them to your own working repo for the first initial steps. OR at least put them under an experimental folder, so others can mute these in their GIT client.