error message is too vague when user has typoed the timestamp

[ronja-ui]

Description
If a user typoes a timestamp or uses not supported timestamp format in earliest or latest, the error message is way too vague:

java.lang.RuntimeException: TimeQualifier conversion error: <2021-01-08> can't be parsed.

A more descriptive error message would be more beneficial. All the user needs to know is:

1. They typoed the timestamp or used a wrong format
2. A hint what formats are accepted

It's easier and quicker to fix the query when the error message offers the correct format right in the UI.

The way to trigger the error message:

%dpl
index=crud earliest=2021-01-08 latest=2021-01-09