Use only Prepared statements for queries

[elpiel]

We currently have places where we don't use prepared statements for queries.
This could lead to bugs if Display and ToSql implementations for the struct are different, however this is not the case at the moment.

• Change all remaining queries to use prepared statement parameters

[elpiel]

There are places that remain which don't use parameters from a prepared statement and instead integrate the values directly into the query.
This will be changed with AIP#61 as a alterations of the code in the places where this happens is needed.

Example of such place is sentry/src/db/event_aggregate.rs:

https://github.com/AdExNetwork/adex-validator-stack-rust/blob/5ed4c4330bb134afb8ce6c3878751f6a25fcb471/sentry/src/db/event_aggregate.rs#L92

[elpiel]

Since the development of AIP#61 #377 and the latest changes in PR #473
all queries that do not use prepared statements have been fixed or removed.