Adding bulk-indexing and improving a bit the name indexing for bleve and elasticsearch (#16704)

* Adding bulk-indexing and improving a bit the name indexing for bleve and elasticsearch

* Update services/searchengine/bleveengine/bleve.go

Co-authored-by: Mario de Frutos Dieguez <mario@defrutos.org>

* Update store/sqlstore/file_info_store.go

Co-authored-by: Mario de Frutos Dieguez <mario@defrutos.org>

* Update store/sqlstore/file_info_store.go

Co-authored-by: Mario de Frutos Dieguez <mario@defrutos.org>

* Adding tests requested in the PR review

* fixing tests

* Adding a feature flag to avoid indexing files before the feature is released

* Fixing i18n

Co-authored-by: Mario de Frutos Dieguez <mario@defrutos.org>
Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

model/feature_flags.go

@@ -24,6 +24,8 @@ type FeatureFlags struct {
 
 	// Feature flags to control plugin versions
 	PluginIncidentManagement string `plugin_id:"com.mattermost.plugin-incident-management"`
+	// Toggle on and off support for Files search
+	FilesSearch bool
 }
 
 func (f *FeatureFlags) SetDefaults() {
@@ -31,6 +33,7 @@ func (f *FeatureFlags) SetDefaults() {
 	f.TestBoolFeature = false
 	f.CloudDelinquentEmailJobsEnabled = false
 	f.CollapsedThreads = false
+	f.FilesSearch = false
 	f.CustomUserStatuses = false
 	f.PluginIncidentManagement = "1.4.0"
 }