Fix grok extractor

[Licenser]

Pull request

Description

The implementation for Clone for the Grok extractor was buggy leading to it loosing all functionality unless the pattern was a full regular expression. This fixes it.

Checklist

• The RFC, if required, has been submitted and approved
• Any user-facing impact of the changes is reflected in docs.tremor.rs
• The code is tested
• Use of unsafe code is reasoned about in a comment
• Update CHANGELOG.md appropriately, recording any changes, bug fixes, or other observable changes in behavior
• The performance impact of the change is measured (see below)

Performance

[codecov]

Codecov Report

Merging #1677 (8f1293e) into main (22fd3a8) will increase coverage by 0.02%.
The diff coverage is 90.00%.

@@            Coverage Diff             @@
##             main    #1677      +/-   ##
==========================================
+ Coverage   87.59%   87.62%   +0.02%     
==========================================
  Files         254      254              
  Lines       50371    50344      -27     
==========================================
- Hits        44122    44113       -9     
+ Misses       6249     6231      -18     

Flag	Coverage Δ
clicommand	14.46% <0.00%> (+0.01%)	⬆️
cliintegration	52.54% <0.00%> (+0.05%)	⬆️
cliunit	13.40% <0.00%> (+<0.01%)	⬆️
unittests	86.40% <90.00%> (+0.02%)	⬆️

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

Impacted Files	Coverage Δ
tremor-script/src/grok.rs	99.01% <83.33%> (+1.86%)	⬆️
tremor-script/src/tilde.rs	83.98% <100.00%> (+0.82%)	⬆️
src/connectors/impls/otel/client.rs	77.22% <0.00%> (-1.00%)	⬇️
src/pipeline.rs	85.67% <0.00%> (-0.29%)	⬇️
src/system/flow.rs	90.20% <0.00%> (-0.19%)	⬇️
tremor-cli/src/test/before.rs	77.77% <0.00%> (ø)
src/connectors/source.rs	87.05% <0.00%> (+0.23%)	⬆️
src/connectors/sink.rs	87.67% <0.00%> (+0.41%)	⬆️
src/connectors/impls/kafka/producer.rs	75.09% <0.00%> (+0.72%)	⬆️
... and 1 more

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[mfelsche]

We should REALLY document that it loads existing patterns from a file. Couldn't find this anywhere in our docs.