ENH: Allow insert/update/delete and files in Extern C

Summary

See https://gitlab.indiscale.com/caosdb/customers/lfpb/management/-/issues/412

Focus

Point the reviewer to the core of the code change. Where should they start
reading? What should they focus on (e.g. security, performance,
maintainability, user-friendliness, compliance with the specs, finding more
corner cases, concrete questions)?

Test Environment

How to set up a test environment for manual testing?

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

@@ -345,7 +345,8 @@ public:
    *
    * A client may request the current status at any time via GetStatus().
    *
-   * Use WaitForIt() to join the back-ground execution of this transaction.
+   * Use WaitForIt() to join the back-ground execution of this transaction, otherwise the behaviour
+   * of getting the ResultSet is undefined.
    */
   auto ExecuteAsynchronously() noexcept -> StatusCode;
 
@@ -353,7 +354,8 @@ public:
    * Join the background execution and return the status when the execution
    * terminates.
    *
-   * Use this after ExecuteAsynchronously().
+   * Use this after ExecuteAsynchronously(), otherwise the TransactionStatus still remains
+   * EXECUTING.
    */
   [[nodiscard]] auto WaitForIt() const noexcept -> TransactionStatus;