Thanks for submitting a PR! Please check the boxes below:

• I have added information to docs/ if required so people know about the feature!
• I have filled in the "Changes" section below?
• I have filled in the "How did you test this code" section below?
• I have used a Conventional Commit title for this Pull Request

Changes

• new utility getUserAgent to get version from composer as flagsmith-ruby-sdk/v4.3.0 or returns flagsmith-php-sdk/unknown (not realistic as the version is required in Gem)
• Added header in API and Analytics requests

How did you test this code?

• Added tests
• used Dummy script and got the desired

Headers configured in Faraday connection:
  Accept: application/json
  Content-Type: application/json
  X-Environment-Key: test-key
  User-Agent: flagsmith-ruby-sdk/4.3.0