feat: pivot click to add filter in canvas

[djbarnwal]

https://linear.app/rilldata/issue/APP-770/click-to-filter-for-pivot-and-table-component

Adds click to filter for pivot and flat table in canvas

Checklist:

• Covered by tests
• Ran it and it works as intended
• Reviewed the diff before requesting a review
• Checked for unhandled edge cases
• Linked the issues it closes
• Checked if the docs need to be updated. If so, create a separate Linear DOCS issue
• Intend to cherry-pick into the release branch
• I'm proud of this work!

[AdityaHegde]

Some UXQA items before I do a code review,

1. Exclude mode breaks the interactions. Selecting values will make the rows disappear vs in leaderboard where they are retained with an x instead of a checkmark in front of values.
2. Clicking on null doesnt add a filter.
3. Filtering from a leaderboard component will not retain other values, only filtering from pivot retains other values.

[djbarnwal]

This will need some more re-work based on https://www.notion.so/rilldata/Click-to-Filter-31bba33c8f57807189f0dd685498438f

[ericokuma]

LGTM!

[AdityaHegde]

Why are we mocking theses? There doesnt seem to be tests for them specifically so would be good to let them work as is. Same for pivot-row-selection.

[djbarnwal]

The mocks make the setup and orchestration easy. Using the real functions would involve complex real world pivot table setup. The current tests focus on the click selection logic specifically. A broader real world test suite can be a follow up for this.