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/VividCortex/mysqlerr/README.md

@@ -0,0 +1,18 @@
+mysqlerr
+========
+
+MySQL Server Error Constants
+
+Covers up to MySQL 5.7.13. Notice that some constants were renamed in later
+versions of MySQL, because they became obsolete. (In case you wonder: the names
+here match the symbols MySQL uses in source code.) Obsolete names haven't been
+changed in this package to avoid breaking code, but you should no longer be
+using them in applications. Here's the full list of changes since this package's
+first version:
+
+| Code | This package | MySQL (as of 5.7.8) |
+| ---: | ------------ | ------------------- |
+| 1150 | ER_DELAYED_CANT_CHANGE_LOCK | ER_UNUSED1 |
+| 1151 | ER_TOO_MANY_DELAYED_THREADS | ER_UNUSED2 |
+| 1165 | ER_DELAYED_INSERT_TABLE_LOCKED | ER_UNUSED3 |
+| 1349 | ER_VIEW_SELECT_DERIVED | ER_VIEW_SELECT_DERIVED_UNUSED |