Source available metrics (#24879)

* Expose metrics under a source available license

* do not assume Cluster()

* allow metrics if licensed or dev

* temporary vet override

* simplify BULID_TAGS handling

* auto clean old imports.go

* fix license listener

* e2e test metrics & license semantics

* update from enterprise

* switch back to mattermost-govet/v2@new now

* update metrics from upstream

* Update license_spec.js

Co-authored-by: Saturnino Abril <saturnino.abril@gmail.com>

* Update license_spec.js

Co-authored-by: Saturnino Abril <saturnino.abril@gmail.com>

* Update e2e-tests/cypress/tests/integration/channels/enterprise/metrics/license_spec.js

Co-authored-by: Saturnino Abril <saturnino.abril@gmail.com>

* Update e2e-tests/cypress/tests/integration/channels/enterprise/metrics/license_spec.js

* split up specs

* require/delete license earlier in e2e test

* expanded expect to debug failures

* more logging

* Revert "more logging"

This reverts commit 0bc513fd926c07a0c6050f4b4c742e856d8dc435.

* e2e: try deleting license first

* update from enterprise

* toggleMetricsOn to work around license delete

* eslint

* ensure admin before deleting license

* update from enterprise

* updates from enterprise

* fix cypress logging

* temp: log at DEBUG for Cypress tests

---------

Co-authored-by: Saturnino Abril <saturnino.abril@gmail.com>
Co-authored-by: Mattermost Build <build@mattermost.com>

server/go.mod

@@ -51,6 +51,7 @@ require (
 	github.com/opentracing/opentracing-go v1.2.0
 	github.com/pkg/errors v0.9.1
 	github.com/prometheus/client_golang v1.17.0
+	github.com/prometheus/client_model v0.5.0
 	github.com/reflog/dateconstraints v0.2.1
 	github.com/rs/cors v1.10.1
 	github.com/rudderlabs/analytics-go v3.3.3+incompatible
@@ -179,7 +180,6 @@ require (
 	github.com/philhofer/fwd v1.1.2 // indirect
 	github.com/pierrec/lz4/v4 v4.1.19 // indirect
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
-	github.com/prometheus/client_model v0.5.0 // indirect
 	github.com/prometheus/common v0.45.0 // indirect
 	github.com/prometheus/procfs v0.12.0 // indirect
 	github.com/redis/go-redis/v9 v9.3.0 // indirect