Extend http proxying timeout

[satvu]

Issue describing the changes in this PR

resolves #1745 in dotnet worker.

Default yarp timeout is 100 seconds (docs) which is shorter than the Antares default for HTTP requests (230s) so we need to set our own default value.

Pull request checklist

• My changes do not require documentation changes
  • Otherwise: Documentation issue linked to PR
• My changes should not be added to the release notes for the next release
  • Otherwise: I've added my notes to release_notes.md
• My changes do not need to be backported to a previous version
  • Otherwise: Backport tracked by issue/PR #issue_or_pr
• My changes do not require diagnostic events changes
  • Otherwise: I have added/updated all related diagnostic events and their documentation (Documentation issue linked to PR)
• I have added all required tests (Unit tests, E2E tests)

Additional information

Filed an issue for http timeout test suite here.