PLT-6965 jira integration (plus plugin scaffolding) (#6918)

* plugin scaffolding / jira integration

* add vendored testify packages

* webhook fix

* don't change i18n ids

* support configuration watching

* add basic jira plugin configuration to admin console

* fix eslint errors

* fix another eslint warning

* polish

* undo unintentional config.json commit >:(

* test fix

* add jira plugin diagnostics, remove dm support, add bot tag, generate web-safe secrets

* rebase, implement requested changes

* requested changes

* remove tests and minimize makefile change

* add missing license headers

* add missing comma

* remove bad line from Makefile

Makefile

@@ -539,6 +539,8 @@ govet:
 	$(GO) vet $(GOFLAGS) ./api || exit 1
 	$(GO) vet $(GOFLAGS) ./api4 || exit 1
 	$(GO) vet $(GOFLAGS) ./app || exit 1
+	$(GO) vet $(GOFLAGS) ./app/plugin || exit 1
+	$(GO) vet $(GOFLAGS) ./app/plugin/jira || exit 1
 	$(GO) vet $(GOFLAGS) ./cmd/platform || exit 1
 	$(GO) vet $(GOFLAGS) ./einterfaces || exit 1
 	$(GO) vet $(GOFLAGS) ./jobs || exit 1