add script_id to user_levels and activities
* migration to add script id to user_levels and activities
* script to copy existing user_levels to new ones for each relevant
  script
* I don't think it's necessary to do the same for activities because we
  don't actually query activities in a script context for any user
  facing features (we use user_level where we need to do something like
  this)
never mind that, never touch the activities table
code to write user_levels with script_ids
Add a default number of example blocks to Contract editor on new function creation
- Auto-populate example blocks with a procedure call
Make default number of example blocks configurable per-level
Update interesting-levels.md
A few nit-pick-y changes & comments from reading code
Move block.moveTo to block.js
Auto-lay-out example and function definition blocks in contract editor
allow admins to censor sharing drawings
Replace static references to `Blockly.functionEditor` with `this`
Fix scope
Merge remote-tracking branch 'origin/non-category-modal-editor' into functional_examples

Conflicts:
	blockly-core/core/function_editor.js
add sql command in comment
Position flyout below last example
- Add optional y-offset to horizontal flyout positioning
- Ignore horizontal flyout height in modal blockspace metrics
created show notes for frozen videos
[Finishes #82528944] Add ability to embed Blockly blocks within multi/match content
webapp console.log, math, and error handling in user program
Initial work on special Frozen "carousel" for code.org/learn.
Add example headers