Feature Request: Open XML config, Remove all button, remember last path

### Feature Description:

I have prepared a fork with a few Trace Viewer - related enhancements:

- Extends OPENED TRACES → Open Trace so that users can load a configuration XML file, which is then sent to the Trace Server. This mimiks Eclipse: https://archive.eclipse.org/tracecompass/doc/stable/org.eclipse.tracecompass.doc.user/Data-driven-analysis.html
- Adds a new OPENED TRACES → Clear Trace Server button, with options to clear:
-- all Trace Server data
-- experiments only
-- configurations only
Similar to https://archive.eclipse.org/tracecompass/doc/stable/org.eclipse.tracecompass.doc.user/Data-driven-analysis.html
- Remembers the last opened path for subsequent file selection.

This PR enables users to load an XML analysis configuration file directly from the extension and provides a convenient way to clear experiments and XML configurations from the Trace Server.

This is intended as the starting point for Arm’s contribution to the Trace Viewer. We plan to use the Trace Server Protocol and extend the Trace Viewer to display Cortex-M trace channels.