Event template search/filter breaks when switching between targets

[andrewazores]

Similar to #263

To reproduce:

• Select the 9093 application
• Navigate to Events/Event Templates
• Click the Filter text box for Templates and enter "prof"
• Observe that the list is updated to show only templates matching this string (ex. Profiling)
• Select the quarkus-run.jar application

Current behaviour:
The templates list is broken. The filter box contains no text, but the templates table/list still contains only the Profiling item. Clicking in the filter box and entering any text updates the filter/resets the view, ex. pressing 'space' resets the view to show all items.

Expected behaviour:
If the filter box is empty, there should be no filtering applied, and all of the templates should be present in the list.
Switching between targets should reset both the filter box and the table state.