feat: switch stfc email to use status actions

[mutambaraf]

Description

This is a pull request to switch the STFC email to use status actions instead of the previously used method.

Motivation and Context

The previous method of handling STFC emails was cumbersome and prone to errors. There was also a need to clean up the code and improve readability. This change simplifies the email handling process and makes the code easier to maintain and understand.

Changes

The primary changes are done in two files: SMTPMailService.ts and stfcEmailHandler.ts.

1. In SMTPMailService.ts, the variable _email has been renamed to emailTemplates for clarity and better readability.
2. In stfcEmailHandler.ts, several unnecessary imports, functions, and variables have been removed. This significantly simplifies the file, making it easier to understand and maintain.
3. The email handling process has been switched to use status actions, which simplifies the process and reduces the potential for errors.

How Has This Been Tested?

Fixes

Part of : UserOfficeProject/issue-tracker#1011

Depends On

https://git.devs.facilities.rl.ac.uk/isisbusapps/BisAppSettings/pulls/453

Tests included/Docs Updated?

• I have added tests to cover my changes.
• All relevant doc has been updated

[bolmsten]

I think this is a good step. In the future it would be good to make the SMTP service less STFC specific, at the moment you have hardcoded values from STFC in the file.

[bolmsten]

@gnyiri

Would be good to do the same for ELI and combine the SMTP services

[gnyiri]

@gnyiri

Would be good to do the same for ELI and combine the SMTP services

We will probably not need our ELI specific SMTP service, the specialized event handler would be enough if the SMTP service will be generic without STFC specific code.

[mutambaraf]

@gnyiri

Would be good to do the same for ELI and combine the SMTP services

I think the best way to solve this is to allow upload of email templates then query the table for uploaded templates. Will create an issue for it.