Use transactions when a series of queries are executed to complete a function

To perform the function of:

- adding a new profile
- editing an existing profile
- deleting a profile

multiple queries are executed on different tables (i.e. INSERT into profiles... + INSERT into profile_group...
These queries should be executed inside a transaction, in order to keep the database status consistent in case of failure of one of them.

See [this example](https://github.com/CodeYourFuture/scot-min-imece/commit/a6252b77083fdccf32f4d333489a9c11dea0c7fb)

No source files, tests, or entry points are named in the issue. Trace the implementations for adding, editing, and deleting profiles, then compare their multi-table queries with the linked transaction example; done means a failure in any query leaves the database consistent.

Written by the indexing model from the issue text.