[FEATURE] Add rest api to get list of trigger types - TRIGGER_TYPE

[rblcoder]

Is your feature request related to a problem?
Currently we need to hard-code list of trigger types in code and need to refer back to this repository from time to time to see if any additional types are added

What solution would you like?
Need to get a list of trigger types returned from a rest api

What alternatives have you considered?
Hard-coding the trigger types in code

Do you have any additional context?
Trigger types can be found here

[eirsep]

@rblcoder Currently each trigger type is associated to specifc monitor type.

We encourage you to raise a PR to add support for such an API if you have a use case to list trigger types but i personally see more value in fetching the monitor types as that will help determine the trigger type

[rblcoder]

@eirsep Would it be better to derive the trigger types from a list of monitor types?
Is that rest API endpoint already available?