Release v0.4.1

[hayk96]

1. What this PR does / why we need it:

• This PR adds several features and fixes which are introduced in the following PRs:
  • https://github.com/hayk96/prometheus-api/pull/43
  • https://github.com/hayk96/prometheus-api/pull/41
  • https://github.com/hayk96/prometheus-api/pull/39
  • https://github.com/hayk96/prometheus-api/pull/37
  • https://github.com/hayk96/prometheus-api/pull/35

2. Make sure that you've checked the boxes below before you submit PR:

• [x] DCO signed
• [x] No conflict with the main branch.