Add a configuration to optionally disable drop with purge

[eric-maynard]

Description

Purging data with background tasks may not be reliable in the even that the Polaris service shuts down before it's able to complete the tasks.

Fixes #269

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• Documentation update
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

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• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• If adding new functionality, I have discussed my implementation with the community using the linked GitHub issue

[dennishuo]

A couple minor things, but high level intent looks good to me

[dennishuo]

A unittest case in BasePolarisCatalogTest could be handy to verify the catalog config override kicking in as expected.

[dennishuo]

LGTM

[RussellSpitzer]

Approved based on @dennishuo 's Review - Thanks!