Add Fabric internal hooks

[lightningforever]

What does this PR do?

Fixes #17755

Adds Fabric-internal hooks that get called automatically.
This small selection of hooks remains undocumented/experimental for now. Subject to change in the future.

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[codecov]

Codecov Report

Merging #17759 (dad3908) into master (e2986fa) will decrease coverage by 23%.
The diff coverage is 100%.

❗ Current head dad3908 differs from pull request most recent head 29a40e1. Consider uploading reports for the commit 29a40e1 to get more accurate results

Additional details and impacted files

@@            Coverage Diff            @@
##           master   #17759     +/-   ##
=========================================
- Coverage      84%      61%    -23%     
=========================================
  Files         419      414      -5     
  Lines       31644    31548     -96     
=========================================
- Hits        26680    19337   -7343     
- Misses       4964    12211   +7247     

[lantiga]

Looks good! We could add (not now is ok) an on_after_backward hook since it's the other event we control.