Consistent flags and CI for --write-secrets=false

[tomhjp]

This PR makes our flags consistent on using dashes instead of underscores as with our other products. To help support that in a forwards-compatible way, I've left --health_addr in there for now (because it's the only underscore argument we've released) but marked it as deprecated, and if someone specifies both --health_addr and --health-addr, the one that occurs later in the command line wins.

This PR also adds a couple of make targets and updated CI config to support running tests with both behaviours of --write-secrets. It's a pretty significant change in the operation of the provider because it controls whether the provider or the driver writes the secrets, so I'd like to keep good test coverage of both flows until --write-secrets=true becomes a deprecated behaviour a few versions down the line.

Both of these entries will get an advanced notice in our next release changelog explaining that they will be a breaking change in a future release, but both can also be fixed by users well ahead of time once the next release is out.

[tomhjp]

I've put a note in the changelog slating --write-secrets=false as the default in 2 major versions from now, as the driver is looking for providers to support it as the default by v0.0.23 which is roughly a month away. See kubernetes-sigs/secrets-store-csi-driver#551 for context.

[jasonodonnell]

LGTM