[feature] Add a request ID and include it in logs (#1476)

This adds a lightweight form of tracing to GTS. Each incoming request is
assigned a Request ID which we then pass on and log in all our log
lines. Any function that gets called downstream from an HTTP handler
should now emit a requestID=value pair whenever it logs something.

Co-authored-by: kim <grufwub@gmail.com>

internal/api/fileserver/fileserver_test.go

@@ -99,7 +99,7 @@ func (suite *FileserverTestSuite) SetupTest() {
 
 func (suite *FileserverTestSuite) TearDownSuite() {
 	if err := suite.db.Stop(context.Background()); err != nil {
-		log.Panicf("error closing db connection: %s", err)
+		log.Panicf(nil, "error closing db connection: %s", err)
 	}
 }