mutual tls client certificates

[ippocratis]

Is your feature request related to a problem? Please describe.
Traccar server is behind reverse proxy with mutual tls
Traccar android client can not connect to server unless it provides a client certificate

Describe the solution you'd like
A settings menu with a file picker to manually add the p12 client cert and the cert password

Describe alternatives you've considered

Additional context
Owntracks have this implemented
https://owntracks.org/booklet/features/tlscert/

It would be great to benefit from the extra security layer mtls can provide
No traccar server work is mantatory as server side a webserver can stand in front traccar providing mtls and reverse proxy