F async execute

Summary

1. Makes ExecuteAsynchronously actually asynchronous.
2. Version bump of grpc to 1.45.2

Focus

Most of the old execution code has been removed from ExecuteAsynchronously and WaitForIt and has been split up into DoExecuteTransaction(), ProcessCall, ProcessTerminated, and ProcessRetrieveResponse.

ExecuteAsynchronously now only start a background thread running DoExecuteTransaction and WaitForIt joins the background thread until it terminates.

Because we deal with multiple thread now, this MR also needed to introduce a mutex/lock system. We have a special non-public macro for this (TRANSACTION_SYNCRONIZED_BLOCK).

Test Environment

Pipelines should be enough. If we encounter problems in the dependent clients (julia, octave) afterwards we will see what we need to do then.

Check List for the Author

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• All automated tests pass
• Reference related Issues
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  • Intent of new code
  • Problems with old code
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Check List for the Reviewer

• I understand the intent of this MR
• All automated tests pass
• Up-to-date CHANGELOG.md
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include/caosdb/file_transmission/download_request_handler.h

@@ -83,7 +83,11 @@ public:
   DownloadRequestHandler(DownloadRequestHandler &&) = delete;
   DownloadRequestHandler &operator=(DownloadRequestHandler &&) = delete;
 
-  void Start() override { OnNext(true); }
+  void Start() override {
+    if (state_ == CallState::NewCall) {
+      OnNext(true);
+    }
+  }
 
   bool OnNext(bool ok) override;