reverseproxy: rework cert logic

9c8f78a059 already fixed many of the cert issues.

However, some issues were caught in the CI:

* The TLS addon has to be rebuilt and not just restarted. For this reason, we now
  move things to a directory instead of mounting files. This way the container is just restarted.

* Cleanups must be driven by the database and not the filesystem . Deleting files on disk or after a restore,
  the certs are left dangling forever in the db.

* Separate the db cert logic and disk cert logic. This way we can sync as many times as we want and whenever we want.

src/domains.js

@@ -243,7 +243,6 @@ async function setConfig(domain, data, auditSource) {
     if (result.affectedRows === 0) throw new BoxError(BoxError.NOT_FOUND, 'Domain not found');
 
     if (fallbackCertificate) await reverseProxy.setFallbackCertificate(domain, fallbackCertificate);
-    if (!_.isEqual(domainObject.tlsConfig, tlsConfig.provider)) await reverseProxy.handleCertificateProviderChanged();
 
     await eventlog.add(eventlog.ACTION_DOMAIN_UPDATE, auditSource, { domain, zoneName, provider });
 }