configure public key and related license variables at build time (#22202)

Instead of being completely hardcoded, public key is now set at build time according to build tag (test key if `testlicensekey` tag is passed to go build, production key otherwise). A `isProdLicensePublicKey` is also available for determining if the prod license key is being used. It is needed for choosing whether to point to production or test environment CWS.

The test license key and CWS url values in this value are set to production values in this PR, but will be updated to the test values once we are ready to do the necessary updates to test environment spinwicks.

Makefile

@@ -33,6 +33,10 @@ IS_CI ?= false
 BUILD_NUMBER ?= $(BUILD_NUMBER:)
 BUILD_DATE = $(shell date -u)
 BUILD_HASH = $(shell git rev-parse HEAD)
+
+# Go tags
+GOTAGS ?= $(GOTAGS:)
+
 # If we don't set the build number it defaults to dev
 ifeq ($(BUILD_NUMBER),)
 	BUILD_DATE := n/a
@@ -41,6 +45,7 @@ endif
 
 ifeq ($(BUILD_NUMBER),dev)
 	export MM_FEATUREFLAGS_GRAPHQL = true
+	GOTAGS += "testlicensekey"
 endif
 
 # Enterprise
@@ -600,7 +605,7 @@ run-server: setup-go-work prepackaged-binaries validate-go-version start-docker
 	@echo Running mattermost for development
 
 	mkdir -p $(BUILD_WEBAPP_DIR)/dist/files
-	$(GO) run $(GOFLAGS) -ldflags '$(LDFLAGS)' $(PLATFORM_FILES) $(RUN_IN_BACKGROUND)
+	$(GO) run $(GOFLAGS) -tags $(GOTAGS) -ldflags '$(LDFLAGS)' $(PLATFORM_FILES) $(RUN_IN_BACKGROUND)
 
 debug-server: start-docker ## Compile and start server using delve.
 	mkdir -p $(BUILD_WEBAPP_DIR)/dist/files
@@ -624,7 +629,7 @@ run-cli: start-docker ## Runs CLI.
 	@echo Running mattermost for development
 	@echo Example should be like 'make ARGS="-version" run-cli'
 
-	$(GO) run $(GOFLAGS) -ldflags '$(LDFLAGS)' $(PLATFORM_FILES) ${ARGS}
+	$(GO) run $(GOFLAGS) -tags $(GOTAGS) -ldflags '$(LDFLAGS)' $(PLATFORM_FILES) ${ARGS}
 
 run-client: ## Runs the webapp.
 	@echo Running mattermost client for development
@@ -681,7 +686,7 @@ restart-client: | stop-client run-client ## Restarts the webapp.
 
 run-job-server: ## Runs the background job server.
 	@echo Running job server for development
-	$(GO) run $(GOFLAGS) -ldflags '$(LDFLAGS)' $(PLATFORM_FILES) jobserver &
+	$(GO) run $(GOFLAGS) -tags $(GOTAGS) -ldflags '$(LDFLAGS)' $(PLATFORM_FILES) jobserver &
 
 config-ldap: ## Configures LDAP.
 	@echo Setting up configuration for local LDAP