Improve Internal Database Index Structure

[alexanderkiel]

Currently we use hashing for values in the SearchParamValueResource, ResourceSearchParamValue and CompartmentSearchParamValueResource indices. As this works well for terminology such as a reasonable number of codings, it doesn't work for identifiers.

We have to remove the value hashing and create separate tables for system URLs because they are just too long.

In the meanwhile, four work rounds are implemented right now:

• Fix Delivering too Many Search Results in Some Cases #1685
• Fix False Positives while Checking Referential Integrity #2015
• Fix Returning Resources with Non-Matching Identifier #2111
• Fix False Positives while Searching for References #2592