Rework behavior of TLS, new default location of keys and certs

[lbetz]

• new location of keys and certs:
  icingaweb2 in /var/lib/icingaweb2/certs
  module: monitoring, icingadb, director, reporting, idoreports, vspheredb
  in each case in /var/lib/icingaweb2//certs
  Only TLS cacert_file, noverify, cipher, capath taken from icingaweb2 by default.

• icingaweb2:
  Parameter db_type is required now.

• director, reporting, x509 and vspheredb module:
  Parameter db_type is required now.
  The service class now is private and will be declared bei the module class and contains to it.
  New parameters to handle the service: manage_service, service_ensure, service_enable and service_user.
  A user (service_user) now is handled if the 'install_method' ist set to 'git' or package. Systemd unit is managed only via git, for package instead a systemd dropin is handled.

• idoreports module:
  Parameter db_type is required now.
  lost all db credentials including TLS, all credentials now are taken from the monitoring module itself.