+ address small nitpicks

Leaving a trailing slash in the context option causes the jira-ruby
gem to add an extra slash in HTTP requests to the URL, preventing
JIRA from working properly.

Closes #42494

Adds a rubocop rule (with autocorrect) to ensure line break after guard clauses.

When an issue is reopened, the action is 'reopen', but the state is 'opened' (as
we don't have a separate 'reopened' state any more).

Because we checked the action in one method and the state in another, this lead
to a weird case where the mesage neither linked to the issue, nor contained an
attachment with its details. Just checking the action is fine, as it's the most
granular.

We used to include the first and last name of the user, but !6624 modified
this to include only the username. Let's compromise and add both in the form
of `First Last (username)`.

Closes #38865

namespace should be lowercased in kubernetes. This is also true for the scenario where the namespace is generated from the project group-name.

Before this fix, I don't know if those emails would work
having newlines in them.