Expose cache policy directive to refetch callers

[calvincestari]

What

This picks up from #1802 to expose the cache policy directive for refetch calls while keeping the internal fetch method private.

Closes #1802

Why

See #1802 (comment).

Tests

None additional - the current WatchQueryTests test cases validate cache/request behaviour so defaulting to anything other than fetchIgnoringCacheData or fetchIgnoringCacheCompletely would fail the tests.

[calvincestari]

I'm opting to close this PR and instead modify the original #1802 PR.

• partly me figuring out how to work with contributor forks
• I think it's a good open-source practice to keep the conversation/work in the original PR since it's better feedback to the contributor