[Partial Fix - #16623]: Fix initialism errors in codebase. (#16877)

* Update files in /app

* Update files in /plugin

* Update files in /store

* Update files in /utils

* Update files in /web

* Update store.go

* Update command_response.go

* check-mocks and check-store-layer checks

* Fix build errors

* Revert "Fix build errors"

This reverts commit 4ee38c3d0bf7bd7d8386f46f0985a0d03245a1d4.

* Update .golangci.yml

* make i18n-extract and make i18n-check

* Commit suggestions

* check-mocks and check-store-layers

* Update en.json

* Update product_notices.go

* Update main.go

* Fix translations

* Regenerate mocks

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>
Co-authored-by: Claudio Costa <cstcld91@gmail.com>

go.tools.mod

@@ -4,9 +4,10 @@ go 1.14
 
 require (
 	github.com/jstemmer/go-junit-report v0.9.1 // indirect
-	github.com/mattermost/mattermost-utilities/mmgotool v0.0.0-20210205183519-d9e542a75ab2 // indirect
+	github.com/mattermost/mattermost-utilities/mmgotool v0.0.0-20210218104610-40d7640e8538 // indirect
 	github.com/philhofer/fwd v1.0.0 // indirect
 	github.com/reflog/struct2interface v0.6.1 // indirect
+	github.com/spf13/cobra v1.1.3 // indirect
 	github.com/tinylib/msgp v1.1.2 // indirect
 	github.com/ttacon/chalk v0.0.0-20160626202418-22c06c80ed31 // indirect
 	github.com/vektra/mockery v1.1.2 // indirect