Extending the db.transaction removal fix to the FhirEngine.search

[LZRS]

          > From discussion with @yigit, this particular read api should be executed independently of any transaction.

Reason (in Yigt's words): The transaction you add there doesn't really help with anything because you are only doing a read inside that transaction and it is a single read. SQLite will already do a "read transaction" for it implicitly, which will make that consistent.

Would you like to work on this @LZRS ?

Would it also affect reads using FhirEngine#search , that joins to other tables?

Originally posted by @LZRS in #2552 (comment)

[aditya-07]

@LZRS The search api may have to do up to three different database calls to full fill a single search based on the search query.
Because of this, we have to consider one of the three cases.

1. Don't remove transaction
2. Remove for single search and keep if include/revInclude is there, so that the all the db queries for a single search happen in database transaction and the results are always correct.
3. Remove for all and be OK with the consequences of maybe divergent results.