tools: Move go.mod & go.sum files to root

Go tooling does not work properly when modifying go files in subdirectories from the root of the IDE.

Consolidate the two go modules in the source tree.
We'll eventually want to move `src/dawn/node/tools` to `tools/src`.

Allows us to type `go test ./...` at the root, and test all go code in
the entire repo.

Bug: dawn:1342
Change-Id: Ie3dd2c89a769cd25c2b68884970ef0f2ba8c7560
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/86532
Commit-Queue: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>

tools/src/go.mod

@@ -1,44 +0,0 @@
-module dawn.googlesource.com/dawn/tools/src
-
-go 1.18
-
-require (
-	github.com/andygrunwald/go-gerrit v0.0.0-20220404064545-525eecd29744
-	github.com/fatih/color v1.13.0
-	github.com/go-git/go-git/v5 v5.4.2
-	github.com/google/go-cmp v0.5.6
-	github.com/sergi/go-diff v1.2.0
-	github.com/shirou/gopsutil v3.21.11+incompatible
-	go.chromium.org/luci v0.0.0-20220412023008-ab2409fe739a
-	golang.org/x/net v0.0.0-20220403103023-749bd193bc2b
-)
-
-require (
-	cloud.google.com/go v0.99.0 // indirect
-	github.com/acomagu/bufpipe v1.0.3 // indirect
-	github.com/go-git/gcfg v1.5.0 // indirect
-	github.com/go-git/go-billy/v5 v5.3.1 // indirect
-	github.com/go-ole/go-ole v1.2.6 // indirect
-	github.com/golang/mock v1.6.0 // indirect
-	github.com/golang/protobuf v1.5.2 // indirect
-	github.com/google/go-querystring v1.1.0 // indirect
-	github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 // indirect
-	github.com/julienschmidt/httprouter v1.3.0 // indirect
-	github.com/klauspost/compress v1.13.5 // indirect
-	github.com/mattn/go-colorable v0.1.9 // indirect
-	github.com/mattn/go-isatty v0.0.14 // indirect
-	github.com/mitchellh/go-homedir v1.1.0 // indirect
-	github.com/tklauser/go-sysconf v0.3.10 // indirect
-	github.com/tklauser/numcpus v0.4.0 // indirect
-	github.com/yusufpapurcu/wmi v1.2.2 // indirect
-	golang.org/x/oauth2 v0.0.0-20211104180415-d3ed0bb246c8 // indirect
-	golang.org/x/sync v0.0.0-20210220032951-036812b2e83c // indirect
-	golang.org/x/sys v0.0.0-20220128215802-99c3d69c2c27 // indirect
-	golang.org/x/text v0.3.7 // indirect
-	google.golang.org/api v0.63.0 // indirect
-	google.golang.org/appengine v1.6.7 // indirect
-	google.golang.org/genproto v0.0.0-20220216160803-4663080d8bc8 // indirect
-	google.golang.org/grpc v1.44.0 // indirect
-	google.golang.org/protobuf v1.27.1 // indirect
-	gopkg.in/warnings.v0 v0.1.2 // indirect
-)