feat(elbv2): regex support for listener conditions

[azatoth]

Issue #36363

Closes #36363

Reason for this change

AWS elbv2 now (since when?) supports regex values for host headers, http headers, and path patterns.

Description of changes

Add regex-based condition methods for ALB listener rules:

• hostHeadersRegex() for host header pattern matching
• httpHeaderRegex() for HTTP header pattern matching
• pathPatternsRegex() for URL path pattern matching

These methods use the regexValues CloudFormation property instead of values, allowing for more flexible pattern matching using regular expressions.

Also add comprehensive validation for all listener condition types:

• Maximum length validation (128 chars for most values, 40 for header names)
• Non-empty value validation where required
• Pattern validation for HTTP request methods
• Maximum count validation (5 items for path patterns, same as before; unknown which number is correct because some pages are saying 3, some are saying 5 and the rest have no idea...)

Describe any new or updated permissions being added

N/A

Description of how you validated changes

Includes unit tests and integration tests for all new functionality.

Checklist

• My code adheres to the CONTRIBUTING GUIDE and DESIGN GUIDELINES

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By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license

[github-actions]

⚠️ Experimental Feature: This security report is currently in experimental phase. Results may include false positives and the rules are being actively refined.
Please try merge from main to avoid findings unrelated to the PR.

---

	Tests	Passed ☑️	Skipped	Failed ❌️
Security Guardian Results	48 ran	47 passed		1 failed

Test	Result
Security Guardian Results
packages/@aws-cdk-testing/framework-integ/test/aws-elasticloadbalancingv2/test/integ.alb.listener-conditions.js.snapshot/aws-cdk-elbv2-alb-listener-conditions-integ.template.json
ec2-no-open-security-groups.guard	❌ failure

• View Security Guardian Results

[github-actions]

⚠️ Experimental Feature: This security report is currently in experimental phase. Results may include false positives and the rules are being actively refined.
Please try merge from main to avoid findings unrelated to the PR.

---

	Tests	Passed ☑️	Skipped	Failed ❌️
Security Guardian Results with resolved templates	48 ran	47 passed		1 failed

Test	Result
Security Guardian Results with resolved templates
packages/@aws-cdk-testing/framework-integ/test/aws-elasticloadbalancingv2/test/integ.alb.listener-conditions.js.snapshot/aws-cdk-elbv2-alb-listener-conditions-integ.template.json
ec2-no-open-security-groups.guard	❌ failure

• View Security Guardian Results with resolved templates