Integrate typescript checking into Jira plugin CI

[mickmister]

Typescript is set up to use for development in the project, but seems to not be checked via CI.

Originally posted by @mickmister in #848 (comment)

[Kshitij-Katiyar]

@mickmister Do we also need to fix all the type errors present in the Jira master branch or do we just need to add a check for typescript in CI YAML file.

[mickmister]

CI won't pass without the type errors being fixed, so the type errors will need to be fixed. If you run into anything particularly complicated, please ping me on this ticket to discuss