Add config options to prometheus exporter

[psx95]

Fixes #2453

Changes

Added the following optional configuration options (booleans) to the prometheus exporter:

• without_units : controls whether to add unit suffixes (e.g. _seconds) to the metric names.
• without_type_suffix: controls whether to add type suffixes (e.g. _total) to the metric names.

• [ ] CHANGELOG.md updated for non-trivial changes
• [X] Unit tests have been added
• [ ] Changes in public API reviewed

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[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 87.91%. Comparing base (497eaf4) to head (0f75727). Report is 144 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3104      +/-   ##
==========================================
+ Coverage   87.12%   87.91%   +0.79%     
==========================================
  Files         200      195       -5     
  Lines        6109     6133      +24     
==========================================
+ Hits         5322     5391      +69     
+ Misses        787      742      -45     

see 98 files with indirect coverage changes

[psx95]

Thanks for the reviews! I made the requested changes.

I sometimes find double negatives in if conditions a little unreadable, hopefully the small comments on top would make things clear.