feat: implement re filter

[dkharms]

Description

This PR introduces support for matching fields (indexed as keyword) against regular expressions.

Closes #347

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[codecov-commenter]

Codecov Report

❌ Patch coverage is 90.16393% with 6 lines in your changes missing coverage. Please review.
✅ Project coverage is 71.54%. Comparing base (6ae5683) to head (2d0c07d).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
parser/seqql_filter.go	75.00%	1 Missing and 1 partial ⚠️
parser/token_re.go	92.59%	1 Missing and 1 partial ⚠️
pattern/pattern.go	75.00%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #348      +/-   ##
==========================================
+ Coverage   71.49%   71.54%   +0.04%     
==========================================
  Files         204      205       +1     
  Lines       14857    14918      +61     
==========================================
+ Hits        10622    10673      +51     
- Misses       3471     3480       +9     
- Partials      764      765       +1     

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[github-actions]

🔴 Performance Degradation

Some benchmarks have degraded compared to the previous run.
Click on Show table button to see full list of degraded benchmarks.

Show table

Name	Previous	Current	Ratio	Verdict
FindSequence_Deterministic/corner-cases-1-4	6ae568	54a732
	58.26 ns/op	65.76 ns/op	1.13	🔴
FindSequence_Random/small-4	6ae568	54a732
	5683.27 MB/s	4255.45 MB/s	0.75	🔴
	45.04 ns/op	60.16 ns/op	1.34	🔴
MutexListAppend-4	6ae568	54a732
	184.44 MB/s	161.62 MB/s	0.88	🔴
	86751404.00 ns/op	98998589.00 ns/op	1.14	🔴

[github-actions]

🔴 Performance Degradation

Some benchmarks have degraded compared to the previous run.
Click on Show table button to see full list of degraded benchmarks.

Show table

Name	Previous	Current	Ratio	Verdict
FindSequence_Random/small-4	6ae568	be91bd
	5683.27 MB/s	4722.01 MB/s	0.83	🔴
	45.04 ns/op	54.21 ns/op	1.20	🔴

[github-actions]

🔴 Performance Degradation

Some benchmarks have degraded compared to the previous run.
Click on Show table button to see full list of degraded benchmarks.

Show table

Name	Previous	Current	Ratio	Verdict
ESBulk-4	b9c2c0	528ea7
	372.00 B/op	437.00 B/op	1.17	🔴
GenerateDocs-4	b9c2c0	528ea7
	935.60 ns/op	1048.00 ns/op	1.12	🔴