[FEATURE] Trigger name should be required in Create alert trigger flyout

[kamingleung]

Is your feature request related to a problem?
When creating a detector alert trigger from the findings page, if a user didn't enter a required field (e.g. Trigger Name), clicking on "Create alert trigger" will let users proceed to create. Trigger name should be required just like in the Create detector flow. Without a trigger name, it is difficult to identify what the alert is about.

What solution would you like?

1. Users go to "Findings" page, click on the bell icon of a finding to open the Create alert trigger flyout.
   
2. When users open the flyout, the Trigger name field should be focused to guide users to fill in a name:

3. On blur, we should display a validation error if the trigger name is left empty. `Trigger name is required.`:

4. If required fields are not filled in, we should keep the Create button disabled:

[jovancacvetkovic]

@kamingleung, @amsiglan I noticed that users can create alerts from a flyout without a rule or severity. Creating a detector also allows these fields to be empty.
Is this OK behavior?

[kamingleung]

@jovancacvetkovic The Rule and Severity fields can be empty. If these two fields are empty, it means it will include any rules and any severities: