Migrate `AthenaQuery` and `SnowflakeQuery` to just `Query`

[ben-githubs]

Background

Panther no longer supports a different backend than Snowflake, and having multiple different fields to specify a scheduled query's SQL body has caused confusion. By pruning all references to AthenaQuery and SnowflakeQuery, we can make our repo consistent with our recommended best practices for customers.

Changes

• removed all AthenaQuery fields
• renamed all SnowflakeQuery fields to Query

Testing

• pat validate passes

[github-actions[bot]]

:scream: looks like some things could be wrong with the packs

[github-actions[bot]]

:scream: looks like some things could be wrong with the packs

[github-actions[bot]]

:scream: looks like some things could be wrong with the packs