[tools] Add 'add-gerrit-hashtags' tool

Parses the CL descriptions and adds missing hashtags to Gerrit changes.

Also add  ./tools/push-to-gerrit which runs this after pushing the local branch's changes to 'main'.

Use this for the VSCode 'push' task.

Change-Id: I4c3f5982f6fdc7c1c6ebe770fc7811b1b38795d1
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/133061
Commit-Queue: Ben Clayton <bclayton@google.com>
Kokoro: Ben Clayton <bclayton@google.com>
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>
diff --git a/go.sum b/go.sum
index a648592..785efdb 100644
--- a/go.sum
+++ b/go.sum
@@ -8,6 +8,8 @@
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/andygrunwald/go-gerrit v0.0.0-20220427111355-d3e91fbf2db5 h1:HBlTlvyq4siv4ZK41DebGIX11/9gFBqUF8G64AePjyQ=
 github.com/andygrunwald/go-gerrit v0.0.0-20220427111355-d3e91fbf2db5/go.mod h1:aqcjwEnmLLSalFNYR0p2ttnEXOVVRctIzsUMHbEcruU=
+github.com/andygrunwald/go-gerrit v0.0.0-20230508072829-423d372345aa h1:bGSzPoUh/2eduqGEk54TCoB4v81MVi6Hr3+fYQwFrBM=
+github.com/andygrunwald/go-gerrit v0.0.0-20230508072829-423d372345aa/go.mod h1:SeP12EkHZxEVjuJ2HZET304NBtHGG2X6w2Gzd0QXAZw=
 github.com/ben-clayton/webidlparser v0.0.0-20210923100217-8ba896ded094 h1:CTVJdI6oUCRNucMEmoh3c2U88DesoPtefsxKhoZ1WuQ=
 github.com/ben-clayton/webidlparser v0.0.0-20210923100217-8ba896ded094/go.mod h1:bV550SPlMos7UhMprxlm14XTBTpKHSUZ8Q4Id5qQuyw=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=