ENH: Support FIND and COUNT queries

Summary

See https://gitlab.indiscale.com/caosdb/customers/lfpb/management/-/issues/399. Introduces FIND and Count queries.

Focus

Most changes are in transaction.h and transaction.cpp.

Test Environment

Unit and integration tests with server in f-grpc-f-query

Check List for the Author

Please, prepare your MR for a review. Be sure to write a summary and a focus and create gitlab comments for the reviewer. They should guide the reviewer through the changes, explain your changes and also point out open questions. For further good practices have a look at our review guidelines

• All automated tests pass
• Reference related Issues
• [ ] Up-to-date CHANGELOG.md
• Annotations in code (Gitlab comments)
  • Intent of new code
  • Problems with old code
  • Why this implementation?

Check List for the Reviewer

• I understand the intent of this MR
• All automated tests pass
• [ ] Up-to-date CHANGELOG.md
• The test environment setup works and the intended behavior is reproducible in the test environment
• In-code documentation and comments are up-to-date.
• Check: Are there specifications? Are they satisfied?

For further good practices have a look at our review guidelines.

include/caosdb/transaction.h

@@ -364,7 +364,7 @@ public:
    * this transaction. In all other cases, the return value will be
    * -1.
    */
-  [[nodiscard]] inline auto GetCountResult() const -> int {
+  [[nodiscard]] inline auto GetCountResult() const -> long {
     return query_count;
   }
 
@@ -379,7 +379,7 @@ public:
   }
 
   /**
-   * Get a JSON representation of the respone.
+   * Get a JSON representation of the response.
    *
    * For debugging.
    */