Improve alert details dialog.

Show time to Alert date column in the Alerts table.
Add Status Description data when displaying an Alert in a popup.
Use title case for key labels when displaying an Alert in a popup.
Update Alert popup title.

Upgrade Angular to 6.1.10 (i.e. latest): upgrade to the HttpClient.
Upgrade Angular Material to 6.4.7 (i.e. latest): upgrade to mat-*
elements, attributes and directives; fix date pickers; fix missing
md-input-containers elements.
Upgrade RxJS to 6.2.2 (i.e. latest). Remove RxJS from devDependencies.
Remove unused codelyzer dependency.
Remove no longer needed md2 dependency.
Add section for the certificate to the user screen.
Add certificate service to support uploading certificates to the server.

Remove ngOnInit where not required; add OnInit implementation where
required.
Use correct components in tests.

Ensure all templateUrls are using correct relative paths.