replace dep with go modules (#16017)

- guide shamelessly stolen from prometheus/prometheus
- updates local interface of oauth exchange
- updates local impl of hclogger
- bump jaeger client version

closes #16088

vendor/github.com/gorilla/websocket/json.go

@@ -9,12 +9,14 @@ import (
 	"io"
 )
 
-// WriteJSON is deprecated, use c.WriteJSON instead.
+// WriteJSON writes the JSON encoding of v as a message.
+//
+// Deprecated: Use c.WriteJSON instead.
 func WriteJSON(c *Conn, v interface{}) error {
 	return c.WriteJSON(v)
 }
 
-// WriteJSON writes the JSON encoding of v to the connection.
+// WriteJSON writes the JSON encoding of v as a message.
 //
 // See the documentation for encoding/json Marshal for details about the
 // conversion of Go values to JSON.
@@ -31,7 +33,10 @@ func (c *Conn) WriteJSON(v interface{}) error {
 	return err2
 }
 
-// ReadJSON is deprecated, use c.ReadJSON instead.
+// ReadJSON reads the next JSON-encoded message from the connection and stores
+// it in the value pointed to by v.
+//
+// Deprecated: Use c.ReadJSON instead.
 func ReadJSON(c *Conn, v interface{}) error {
 	return c.ReadJSON(v)
 }