KSM-389: Add regex pattern support to records data source

[stas-schaller]

Summary

Implements regex pattern matching for the secretsmanager_records data source, allowing users to filter records by title using Go regular expressions.

Changes

New Feature

• title_patterns parameter: Accepts list of regex patterns to match against record titles
• Pattern validation: Compiles and validates patterns at runtime with clear error messages
• Combined queries: Supports mixing UIDs, exact titles, and regex patterns in single data source
• Optimization: Fetches all records once when patterns are used (same as titles behavior)

Tests Added

• TestAccDataSourceRecords_WithTitlePatterns: Basic pattern matching functionality
• TestAccDataSourceRecords_InvalidPattern: Invalid regex error handling
• TestAccDataSourceRecords_CombinedWithPatterns: Mixed UIDs, titles, and patterns
• TestAccDataSourceRecords_MultiplePatterns: Multiple pattern support

Documentation

• Updated docs/data-sources/records.md with regex pattern examples
• Added practical examples to examples/data-sources/records.tf
• Documented performance considerations for pattern matching

Example Usage

data "secretsmanager_records" "production_dbs" {
  title_patterns = [
    "^Production.*Database$",
    "^Prod.*DB.*"
  ]
}

Testing

Run acceptance tests with:

TF_ACC=1 go test ./secretsmanager -v -run TestAccDataSourceRecords_WithTitlePatterns
TF_ACC=1 go test ./secretsmanager -v -run TestAccDataSourceRecords_InvalidPattern
TF_ACC=1 go test ./secretsmanager -v -run TestAccDataSourceRecords_CombinedWithPatterns
TF_ACC=1 go test ./secretsmanager -v -run TestAccDataSourceRecords_MultiplePatterns

Related Issues

• GitHub Issue: Feature Request - be able to load records by title #14
• Jira: KSM-389