2.x Add missing query() method to Timber\PostQuery

[gchtr]

Ticket:

• Fixes v2.0 A way to get the query object from Timber::get_posts() #2605.

Issue

The get_query() method didn’t make it over to 2.x.

Solution

This pull request:

• Adds the missing method and renames from get_query() to query() to match the naming convention.
• Deprecates the get_query() method.
• Adds a test.
• Updates the Upgrade Guide.

Impact and Usage Changes

Mentioned in the Upgrade Guide.

Considerations

–

Testing

Yes.