This takes the TLS Error Reporting functionality used in the aboutNetError.xhtml
and aboutCertError.xhtml error pages and moves it to its own component. This
allows us to make use of this same error reporting functionality from elsewhere.
Notably, this allows us to send error reports for issues that occur when loading
subresources.
The xpcshell test included is in security/manager/ssl/tests because we need to
make use of tlsserver functionality from the PSM tests.
Mark Goodwin