Support logging in directly to the provider when pushing OCI artifacts

I've noticed during CI, that the current command
already expected a configured Docker client to
push artifacts to authenticated registries.

Some users might not want to have the Docker client
in their process (like a CI job) or build an handcrafted
config.json file.

This would allow this kind of behavior:

```
flux push artifact oci://my-registry.dev/foo:v1 \
  --source xxx \
  --revision xxx \
  --path . \
  --creds $TOKEN # Authenticate via "Bearer $TOKEN" Authorization header
```

Or via Autologin:

```
flux push artifact oci://012345678901.dkr.ecr.us-east-1.amazonaws.com/foo:v1 \
  --source xxx \
  --revision xxx \
  --path . \
  --provider aws
```

This has been implemented for:

* flux push artifact
* flux list artifact
* flux tag artifact
* flux pull artifact

This will require another PR in https://github.com/fluxcd/pkg/pull/352

Signed-off-by: Adrien Fillon <adrien.fillon@manomano.com>

go.mod

@@ -14,7 +14,7 @@ require (
 	github.com/fluxcd/notification-controller/api v0.25.2
 	github.com/fluxcd/pkg/apis/meta v0.15.0
 	github.com/fluxcd/pkg/kustomize v0.7.0
-	github.com/fluxcd/pkg/oci v0.8.0
+	github.com/fluxcd/pkg/oci v0.9.0
 	github.com/fluxcd/pkg/runtime v0.18.0
 	github.com/fluxcd/pkg/sourceignore v0.2.0
 	github.com/fluxcd/pkg/ssa v0.19.0
@@ -57,6 +57,9 @@ replace gopkg.in/yaml.v3 => gopkg.in/yaml.v3 v3.0.1
 
 require (
 	cloud.google.com/go v0.99.0 // indirect
+	github.com/Azure/azure-sdk-for-go/sdk/azcore v1.1.2 // indirect
+	github.com/Azure/azure-sdk-for-go/sdk/azidentity v1.1.0 // indirect
+	github.com/Azure/azure-sdk-for-go/sdk/internal v1.0.0 // indirect
 	github.com/Azure/go-ansiterm v0.0.0-20210617225240-d185dfc1b5a1 // indirect
 	github.com/Azure/go-autorest v14.2.0+incompatible // indirect
 	github.com/Azure/go-autorest/autorest v0.11.27 // indirect
@@ -64,10 +67,12 @@ require (
 	github.com/Azure/go-autorest/autorest/date v0.3.0 // indirect
 	github.com/Azure/go-autorest/logger v0.2.1 // indirect
 	github.com/Azure/go-autorest/tracing v0.6.0 // indirect
+	github.com/AzureAD/microsoft-authentication-library-for-go v0.5.1 // indirect
 	github.com/BurntSushi/toml v1.0.0 // indirect
 	github.com/MakeNowJust/heredoc v1.0.0 // indirect
 	github.com/Microsoft/go-winio v0.5.2 // indirect
 	github.com/acomagu/bufpipe v1.0.3 // indirect
+	github.com/aws/aws-sdk-go v1.44.84 // indirect
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cespare/xxhash/v2 v2.1.2 // indirect
 	github.com/chai2010/gettext-go v1.0.2 // indirect
@@ -97,6 +102,7 @@ require (
 	github.com/go-openapi/jsonreference v0.20.0 // indirect
 	github.com/go-openapi/swag v0.21.1 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/golang-jwt/jwt v3.2.1+incompatible // indirect
 	github.com/golang-jwt/jwt/v4 v4.4.1 // indirect
 	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
@@ -118,10 +124,12 @@ require (
 	github.com/imdario/mergo v0.3.12 // indirect
 	github.com/inconshreveable/mousetrap v1.0.0 // indirect
 	github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 // indirect
+	github.com/jmespath/go-jmespath v0.4.0 // indirect
 	github.com/josharian/intern v1.0.0 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
 	github.com/kevinburke/ssh_config v0.0.0-20201106050909-4977a11b4351 // indirect
 	github.com/klauspost/compress v1.15.8 // indirect
+	github.com/kylelemons/godebug v1.1.0 // indirect
 	github.com/liggitt/tabwriter v0.0.0-20181228230101-89fcab3d43de // indirect
 	github.com/mailru/easyjson v0.7.7 // indirect
 	github.com/mattn/go-ciede2000 v0.0.0-20170301095244-782e8c62fec3 // indirect
@@ -142,6 +150,7 @@ require (
 	github.com/opencontainers/go-digest v1.0.0 // indirect
 	github.com/opencontainers/image-spec v1.0.3-0.20220114050600-8b9d41f48198 // indirect
 	github.com/peterbourgon/diskv v2.0.1+incompatible // indirect
+	github.com/pkg/browser v0.0.0-20210911075715-681adbf594b8 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/prometheus/client_golang v1.13.0 // indirect
 	github.com/prometheus/client_model v0.2.0 // indirect