Adds ability to force HTTP Basic when fetching from git repos

[joaopapereira]

What this PR does / why we need it:

Enable the vendir ability to force HTTP Basic when fetching from a git repository.

Which issue(s) this PR fixes:

Fixes #1485

Does this PR introduce a user-facing change?

Allow users to define forceHTTPBasicAuth in the fetch phase.

Additional Notes for your reviewer:

Review Checklist:

• Follows the developer guidelines
• Relevant tests are added or updated
• Relevant docs in this repo added or updated
• Relevant carvel.dev docs added or updated in a separate PR and there's
  a link to that PR
• Code is at least as readable and maintainable as it was before this
  change

[praveenrewar]

Changes looks good to me, I am not sure why the tests are timing out in a kind cluster and that too after 6 hours even though we have a timeout of 60m.
One thing I noticed it that we have missed updating golang version in the kind action (cc @sethiyash)
Also, could we try to show the test logs instead of pushing them to a file and see where the timeout is happening?

[sethiyash]

Ah! Missed it somehow, Raised this separate PR for bumping go version in kind GH action.
cc: @praveenrewar

[joaopapereira]

I just rebased with develop branch let us see if it goes through 😄

[praveenrewar]

LGTM!