detect/transforms: test in place modifications of buffers

[catenacyber]

Link to ticket: https://redmine.openinfosecfoundation.org/issues/
https://redmine.openinfosecfoundation.org/issues/7409

Describe changes:

• detect/transforms: fix and test in place modifications of buffers (aka do not use memcpy)

#12193 with clippy fixes

[victorjulien]

what is the "test" reference in the commit message? If this PR is a test, then it should just be a draft.

[catenacyber]

what is the "test" reference in the commit message?

cargo unit tests

If this PR is a test, then it should just be a draft.

It is not a draft

[codecov]

Codecov Report

Attention: Patch coverage is 98.86364% with 1 line in your changes missing coverage. Please review.

Project coverage is 83.16%. Comparing base (ae10fc3) to head (83aba2e).

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #12194      +/-   ##
==========================================
- Coverage   83.16%   83.16%   -0.01%     
==========================================
  Files         912      912              
  Lines      257066   257124      +58     
==========================================
+ Hits       213797   213843      +46     
- Misses      43269    43281      +12     

Flag	Coverage Δ
fuzzcorpus	61.01% <72.72%> (+0.03%)	⬆️
livemode	19.41% <0.00%> (-0.01%)	⬇️
pcap	44.44% <24.24%> (+0.01%)	⬆️
suricata-verify	62.70% <90.90%> (-0.01%)	⬇️
unittests	59.18% <93.18%> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

[victorjulien]

what is the "test" reference in the commit message?

cargo unit tests

If this PR is a test, then it should just be a draft.

It is not a draft

The language confuses me, making me think the commit is a test, an experiment.

Would the following reflect your intent?

detect/transforms: in place modifications of buffers

As is the case when chaining multiple transforms.

Add tests.

[catenacyber]

Putting

detect/transforms: in place modifications of buffers
    
    As is the case when chaining multiple transforms.
    Avoids using memcpy in these cases.
    
    Add tests for these cases.
    
    Ticket: 7409

[catenacyber]

Next in #12200

My intent was to highlight the testing part, but not to confuse...