buildx/util/buildflags
Justin Chadwell c2e11196dd controller: handle attestation options across api
We can perform all attestation processing, handling how the sbom and
provenance arguments interact on the client, while applying defaults on
the server.

Additionally, this allows us to start pulling fields out of CommonOpts.

Signed-off-by: Justin Chadwell <me@jedevc.com>
..
attests.go controller: handle attestation options across api
cache.go controller: strongly type the controller api
context.go controller: strongly type the controller api
entitlements.go build: split buildflags package
export.go controller: strongly type the controller api
secrets.go controller: strongly type the controller api
ssh.go controller: strongly type the controller api