pcrlock: add "is-supported" verb that checks if the local TPM supports the commands...

pcrlock: add "is-supported" verb that checks if the local TPM supports the commands we need for pcrlock

systemd-pcrlock requires support for the PolicyAuthorizeNV command,
which is not implemented in the first TPM2 releases. We also strictly
require SHA-256 support. Hence add a tool for checking for both of
these.

This is a tighter version of "systemd-analyze has-tpm2", that checks for
the precise feature that systemd-pcrlock needs, on top of basic TPM2
functionality.

Fixes: #37607