Introduce networkingPrivate.getCertificateLists

This CL:
* Adds NetworkCertificateHandler to maintain lists of network
  certificates (Server CA and User/Client).
* Adds a ClientCertPKCS11Id property to ONC to allow configuration
  UI to use ONC to specify a PKCS#11 certificate identifier.
* Adds getCertificateLists to networkingPrivate and networking.onc.

BUG=380937
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2891453002
Cr-Commit-Position: refs/heads/master@{#474836}
39 files changed