Add the API for search files (#15605)

* Adding search files api

* Fixing golangci-lint

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

* Add content extraction config migration

* Fixing a problem with document extraction

* Unapplying certain changes moved to other PR

* Fixing tests

* Making extract content app migration a private method

* Addressing PR review comments

* Addressing PR review comments

* Adding feature flag

* Removing debug string

* Fixing imports

* Fixing linting errors

* Do not migrate the config if the feature flag is not enabled

* Fix tests

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

model/config.go

@@ -335,6 +335,7 @@ type ServiceSettings struct {
 	PostEditTimeLimit                                 *int     `access:"user_management_permissions"`
 	TimeBetweenUserTypingUpdatesMilliseconds          *int64   `access:"experimental,write_restrictable,cloud_restrictable"`
 	EnablePostSearch                                  *bool    `access:"write_restrictable,cloud_restrictable"`
+	EnableFileSearch                                  *bool    `access:"write_restrictable"`
 	MinimumHashtagLength                              *int     `access:"environment,write_restrictable,cloud_restrictable"`
 	EnableUserTypingMessages                          *bool    `access:"experimental,write_restrictable,cloud_restrictable"`
 	EnableChannelViewedMessages                       *bool    `access:"experimental,write_restrictable,cloud_restrictable"`
@@ -537,6 +538,10 @@ func (s *ServiceSettings) SetDefaults(isUpdate bool) {
 		s.EnablePostSearch = NewBool(true)
 	}
 
+	if s.EnableFileSearch == nil {
+		s.EnableFileSearch = NewBool(true)
+	}
+
 	if s.MinimumHashtagLength == nil {
 		s.MinimumHashtagLength = NewInt(3)
 	}
@@ -1353,6 +1358,8 @@ type FileSettings struct {
 	DriverName              *string `access:"environment,write_restrictable,cloud_restrictable"`
 	Directory               *string `access:"environment,write_restrictable,cloud_restrictable"`
 	EnablePublicLink        *bool   `access:"site,cloud_restrictable"`
+	ExtractContent          *bool   `access:"environment,write_restrictable"`
+	ArchiveRecursion        *bool   `access:"environment,write_restrictable"`
 	PublicLinkSalt          *string `access:"site,cloud_restrictable"`                           // telemetry: none
 	InitialFont             *string `access:"environment,cloud_restrictable"`                    // telemetry: none
 	AmazonS3AccessKeyId     *string `access:"environment,write_restrictable,cloud_restrictable"` // telemetry: none
@@ -1396,6 +1403,14 @@ func (s *FileSettings) SetDefaults(isUpdate bool) {
 		s.EnablePublicLink = NewBool(false)
 	}
 
+	if s.ExtractContent == nil {
+		s.ExtractContent = NewBool(false)
+	}
+
+	if s.ArchiveRecursion == nil {
+		s.ArchiveRecursion = NewBool(false)
+	}
+
 	if isUpdate {
 		// When updating an existing configuration, ensure link salt has been specified.
 		if s.PublicLinkSalt == nil || *s.PublicLinkSalt == "" {