reduce surface area

[chadwhitacre]

Turn off tipping in the UI, the JSON API, and the Python API. After this PR, there should be no more code using the tips table. Reduce the surface area for changes by removing code we won't need under the Teams system.

[chadwhitacre]

Incorporates #3403.

[chadwhitacre]

Where are all the places where the Python API interacts with the tips table?

[chadwhitacre]

Here's what I can find:

✓ _check_tips
✓ _check_orphans_no_tips

✓ Participant.update_number
  Participant.clear_tips_giving - close
  Participant.clear_tips_receiving - close
  Participant.update_giving - team takes, exchange routes, setting tips, take over
  Participant.update_receiving - team takes, setting tips, take over
  Participant.set_tip_to - {tip,tips}.json, close, throughout the test suite
  Participant.get_tip_to - tip widget, old button widget, pricing
  Participant.get_tip_distribution - stats, receiving page
  Participant.get_giving_for_profile - giving page, tips.json, close
  Participant.get_tips_receiving - unused!
  Participant.get_current_tips - tips.json
  Participant.take_over - take over
  Participant.final_check - archive, close

  www/about/stats.spt
  www/about/tip-distribution.json.spt

[chadwhitacre]

Here's the behavior this PR should implement:

1. the ability to view, set, or modify a tip should be removed from the UI
2. the ability to view, set, or modify a tip should be removed from the JSON API
3. any Python function that directly interacts with the tips or current_tips should raise NotImplementedError (users shouldn't ever hit this after 1 and 2, but just in case)
4. the Giving page should show empty

[chadwhitacre]

The max tip limit interacts with the number attribute in such a way that this entanglement should be undone as part of this PR (not on a separate PR or we'll introduce a race condition).

[chadwhitacre]

This PR can archive the tips table in its branch.sql.

[chadwhitacre]

Here are the parts of the UI that touch tips:

• closing accounts
• updating team takes
• adding/updating exchange routes
• setting tips
• merging accounts
• tips.json
• the old button widget
• the pricing page
• the stats page
• the receiving page
• the giving page
• archiving accounts

In other words, quite a bit of it, as well as quite a bit of the test suite. Hmm ...

[chadwhitacre]

Revised scope for this PR: let's reduce our surface area for changes to Participant.