feat(appium): show spinner during extension uninstall

[eglitise]

Proposed changes

The current process of uninstalling an extension doesn't give the user enough information. In my experience it always takes at least 10 seconds, during which the console does not show anything. This PR makes it so that a spinner is now shown during the uninstall operation.

Types of changes

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• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices apply)

Checklist

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• I have read the CONTRIBUTING doc
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• Lint and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added the necessary documentation (if appropriate)
• Any dependent changes have been merged and published in downstream modules

[KazuCocoa]

makes sense