Test: ripgrep search in extension host

[roblourens]

Test for #47058 (part 2)

Complexity: 3

• Mac @sandy081
• Windows @weinand

Steps

• Set "search.enableSearchProviders": true to enable the search-rg extension
• Try every text search and quickopen scenario you can think of
  • Search flags - case-sensitivity, whole word, etc
  • Includes/excludes
  • Search settings like followSymlinks
  • Multiroot workspace
• If you file an issue, look up the logs/errors from the search under the search-rg output channel