Make all modification methods respect `prune_previous_versions`

[qc00]

Is your feature request related to a problem? Please describe.

Some methods in library.py do not respect the prune_previous_versions library option. This makes the API inconsistent.

Discovered in #705

Describe the solution you'd like

• Make sort_merge_internal, sort_index, delete_range_internal and defragment_symbol_data C++ methods accept an extra argument and call write_version_and_prune_previous_if_needed instead of write_version
• Make the corresponding Python methods check the library option and pass it to C++. Also, consider adding a parameter to allow the user to override on each call.
• [x] Thoroughly check if there are other incorrect uses of write_version
• [x] Consider if we need to bump the major version

Describe alternatives you've considered

• Leave the methods unchanged, which might lead to the original cause of #705 where a user unknowingly leave thousands of versions behind.
• Improve the documentation to ask the user to call prune_previous_versions after such methods. This is inefficient as the version chain might need reloading by then.

[poodlewars]

Some of these might already be fixed, we should check.

Step 1 of this should be a writeup with analysis of the current state of prune previous versions.

Step 2 tests reproducing the inconsistencies.

Step 3 fixes.

[phoebusm]

• sort_merge -> sort_merge_internal: prune_previous not available
• sort_index: prune_previous not available
• delete_range -> delete_range_internal: prune_previous not available
• defragment_symbol_data: prune_previous not available