HPCC-31676 Replace ICU-based regex with PCRE2

[dcamper]

This replaces regex support for the UNICODE data type.

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• [ ] This change is a bug fix (non-breaking change which fixes an issue).
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• [x] This change is a breaking change (fix or feature that will cause existing behavior to change).
• [ ] This change alters the query API (existing queries will have to be recompiled)

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Testing:

[github-actions[bot]]

Jira Issue: https://hpccsystems.atlassian.net//browse/HPCC-31676

Jirabot Action Result: Workflow Transition: Merge Pending Updated PR

[dcamper]

@ghalliday squashed, ready for merge.

[GordonSmith]

@ghalliday looks like we could remove the io and tu components - but not because of this PR: https://hpccsystems.atlassian.net/browse/HPCC-31764