Guard in QueryCompilerCaster to allow a QC to override casting behavior

[sfc-gh-jkew]

Sometimes we may want to control how the QueryCompilerCaster behaves on a QC by QC basis. The QueryCompilerCaster is only used for the NativePandas QC; but Snowflake would like to add it to the Snowflake QC as well.

We also want to make sure that users do not accidentally download their entire warehouse, so I would like to propose the following approach:

1. Implement a function, BaseQueryCompiler::allow_coercion_to(OtherQueryCompiler) which will return true by default and false if coercion should not occur.
2. In the QueryCompilerCaster we gate the coercion based on the argument's QC
3. If the argument cannot be coerced ( or casted ) then we emit an error
4. If the argument can be coerced we perform the cast as normal

This should allow for the same behavior for existing OSS engines, but allow for some more discretion for engines which want prevent downloading an entire warehouse.

Thoughts @anmyachev @devin-petersohn @mvashishtha

I can start work on a PR for this if this seems pretty reasonable.

[sfc-gh-jkew]

The consensus is that we should implement a symmetric version where A op B and B op A will result in the same QC. This will be a bit more work, but doable.