refactor(extensions)!: refactor the extensions URLs and errors (#1636)

BREAKING CHANGE: The functionality provided by the mgmt endpoint has beed redesigned - see details below
BREAKING CHANGE: The API keys endpoint has been moved -  see details below
BREAKING CHANGE: The mgmt extension config has been removed - endpoint is now enabled by having both the search and the ui extensions enabled
BREAKING CHANGE: The API keys configuration has been moved from extensions to http>auth>apikey

mgmt and imagetrust extensions:
- separate the _zot/ext/mgmt into 3 separate endpoints: _zot/ext/auth, _zot/ext/notation, _zot/ext/cosign
- signature verification logic is in a separate `imagetrust` extension
- better hanling or errors in case of signature uploads: logging and error codes (more 400 and less 500 errors)
- add authz on signature uploads (and add a new middleware in common for this purpose)
- remove the mgmt extension configuration - it is now enabled if the UI and the search extensions are enabled

userprefs estension:
- userprefs are enabled if both search and ui extensions are enabled (as opposed to just search)

apikey extension is removed and logic moved into the api folder
- Move apikeys code out of pkg/extensions and into pkg/api
- Remove apikey configuration options from the extensions configuration and move it inside the http auth section
- remove the build label apikeys

other changes:
- move most of the logic adding handlers to the extensions endpoints out of routes.go and into the extensions files.
- add warnings in case the users are still using configurations with the obsolete settings for mgmt and api keys
- add a new function in the extension package which could be a single point of starting backgroud tasks for all extensions
- more clear methods for verifying specific extensions are enabled
- fix http methods paired with the UI handlers
- rebuild swagger docs

Signed-off-by: Andrei Aaron <aaaron@luxoft.com>

pkg/test/common.go

@@ -43,6 +43,7 @@ import (
 	"github.com/sigstore/cosign/v2/cmd/cosign/cli/generate"
 	"github.com/sigstore/cosign/v2/cmd/cosign/cli/options"
 	"github.com/sigstore/cosign/v2/cmd/cosign/cli/sign"
+	"golang.org/x/crypto/bcrypt"
 	"gopkg.in/resty.v1"
 	"oras.land/oras-go/v2/registry"
 	"oras.land/oras-go/v2/registry/remote"
@@ -126,6 +127,17 @@ func MakeHtpasswdFile() string {
 	return MakeHtpasswdFileFromString(content)
 }
 
+func GetCredString(username, password string) string {
+	hash, err := bcrypt.GenerateFromPassword([]byte(password), 10)
+	if err != nil {
+		panic(err)
+	}
+
+	usernameAndHash := fmt.Sprintf("%s:%s", username, string(hash))
+
+	return usernameAndHash
+}
+
 func MakeHtpasswdFileFromString(fileContent string) string {
 	htpasswdFile, err := os.CreateTemp("", "htpasswd-")
 	if err != nil {