We re-require templates.ts before testing each
new test module during the node tests.
This makes it so that if we make mocks in two
different tests, where such mocks influence
how the Handlebars helpers work, then both
tests will have registered their own copies
of the Handlebars helpers.
'Quote message' is a more accurate decription, as this option inserts
the quoted text into whatever message you're composing or editing;
it does not necessarily start a new reply.
Fixes first part of #31953.
