Add verb-dependent token mode

[mrj]

The Instagram API uses :query token mode for GET requests and :header mode for POST and DELETE requests, not only for endpoint calls but for getting and refreshing long-lived tokens. So instead of a fixed mode, an AccessToken needs its mode to to be request-verb-dependent. This PR implement this.

Two things I haven't done:

1. Allow the mode to also be dependent on the path and even other options, and
2. Test an invalid mode. I couldn't work out how to stop RSpec using

block_is_expected.to raise_error("invalid :mode option of #{mode}")

from earlier in the spec file. Not that important given that the normal mode-switching works.

[coveralls]

Pull Request Test Coverage Report for Build 17541833529

Details

• 5 of 5 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 100.0%

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Totals
Change from base Build 17540447593:	0.0%
Covered Lines:	520
Relevant Lines:	520

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💛 - Coveralls

[pboling]

@mrj Thanks for this. Reviewing it now, but just noticing that the three failures are probably due to RuboCop style.

First try:

bin/rake rubocop_gradual:autocorrect

If it fails you can either fix them, or punt them into the future, and run:

bin/rake rubocop_gradual:force_update

[pboling]

@mrj Also, we are working on things at the same time, so please rebase on latest main!

[pboling]

LGTM, just needs rebase and style linting.

[pboling]

I'll fix the style in post ;) Merging