Link account id with the external user store (#184)

* get account id from access token claim

* use GetOrCreateAccountByUser and add test

* correct account id claim

* remove unused account

* Idp manager interface

* auth0 idp manager

* use if instead of switch case

* remove unnecessary lock

* NewAuth0Manager

* move idpmanager to its own package

* update metadata when accountId is not supplied

* update tests with idpmanager field

* format

* new idp manager and config support

* validate if we fetch the interface before converting to string

* split getJWTToken

* improve tests

* proper json fields and handle defer body close

* fix ci lint notes

* documentation and proper defer position

* UpdateUserAppMetadata tests

* update documentation

* ManagerCredentials interface

* Marshal and Unmarshal functions

* fix tests

* ManagerHelper and ManagerHTTPClient

* further tests with mocking

* rename package and custom http client

* sync local packages

* remove idp suffix

management/server/idp/util.go

@@ -0,0 +1,13 @@
+package idp
+
+import "encoding/json"
+
+type JsonParser struct{}
+
+func (JsonParser) Marshal(v interface{}) ([]byte, error) {
+	return json.Marshal(v)
+}
+
+func (JsonParser) Unmarshal(data []byte, v interface{}) error {
+	return json.Unmarshal(data, v)
+}