Flag to avoid prerequisite of tests having to run in a host application.

[michael-zimmermann]

See issue #229

[chwo]

@RoyalPineapple Pinging you since you published the last releases.

I am experiencing the same issue that the accessibilityImage assertion crashes when run inside SPM. I can confirm that this is solved by this PR so I would love to see that fix merged. Is there anything blocking this?

[albsala-backmarket]

Hi there! Is there any progress here? We'd appreciate if this is fixed. Thank you!
cc @RoyalPineapple @NickEntin

[RoyalPineapple]

This looks like a reasonable change. I don't have any objection to this being configurable.

[albsala-backmarket]

Hey @RoyalPineapple thank you for the approval ❤️!
Not sure if we need something else to merge this PR and close the issue?

[NickEntin]

Apologies for the slow response here. This change feels like it introduces a pretty big footgun into the library. As @szotp's example in the linked issue illustrates, the behavior when running outside a host application is unpredictable and can give some very deceptive test results. While it's definitely an unfortunate requirement, I'd highly recommend reverting this change, since setting this parameter to false essentially means you can't trust the correctness of the resulting snapshots.