Add pixels for adding favorites with autocomplete

[dus7]

Task/Issue URL: https://app.asana.com/0/0/1208413911032918/f
Tech Design URL:
CC:

Description:

Adds pixels reporting as described in task.

Steps to test this PR:
Verify pixels are sent according to the mentioned task on:

1. "+" button in favorites collection is pressed.
2. Favorite is added using autocomplete result.
3. "Add custom website" button is pressed.
4. Favorite is saved using custom edit.
   1. Bookmark is saved instead of favorite.
5. Custom editing is cancelled.
6. Started editing newly added favorite from action message.

Definition of Done (Internal Only):

• Does this PR satisfy our Definition of Done?

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Internal references:

Software Engineering Expectations
Technical Design Template