Measure usage of Special:Search did you mean
Data recorded:
- How many results the user was shown for their query
- Whether the user was shown a did you mean result
- Whether the user clicked on the did you mean result
Statistics that should be computable from this:
- Percentage of queries where the user was shown a "Did you mean" result
- Percentage of queries where, having been shown a "Did you mean" result, the user clicked on that result
Bug: T105201
Change-Id: I28d0aa860b3fd5cf865b52c774fe082f00ce475a