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/prometheus/common/expfmt/text_parse.go

@@ -359,7 +359,7 @@ func (p *TextParser) startLabelValue() stateFn {
 		}
 		return p.readingValue
 	default:
-		p.parseError(fmt.Sprintf("unexpected end of label value %q", p.currentLabelPair.Value))
+		p.parseError(fmt.Sprintf("unexpected end of label value %q", p.currentLabelPair.GetValue()))
 		return nil
 	}
 }