Adding better error/exception handling to the Events/Alerts table if the search query entered is not parseable

[janheise]

Description

Prior to this PR, the widgets on the page would fail after a time with an exception that was not always helpful.
Now we return an empty result which signifies that the query did not have any results.

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Refactoring (non-breaking change)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have requested a documentation update.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.