MM-17912: Allow searching for files through plugin API (#13647)

* constants and options for getting files

* Method to get files with options

* Add i18n strings for en

* Add API methods for getting files with options

* gofmt -s file

* explicitly set create at in tests

* use greater than nanosecond time difference for tests

* use gte instead of gt for getting files by created time

* use created at time as default sort order for getting file infos

* use explicit inline strings instead of format strings

* join tables only when required

* use if as secondary sort, and update tests

* update field docs to reflect previous changes

* make page and perPage get options as required

* add json struct tags to GetFileOptions

* bump minimum server versioni

* remove sorting by username and channelname

* use bool for sort order type

* use FileInfo prefix instead of just File

* clearer comments

* use zero-based page numbering

* test filtering by user and channel

* remove unnecessary whitespace

* use int instead of uint for page and perPage arguments

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

plugin/plugintest/api.go

@@ -1000,6 +1000,31 @@ func (_m *API) GetFileInfo(fileId string) (*model.FileInfo, *model.AppError) {
 	return r0, r1
 }
 
+// GetFileInfos provides a mock function with given fields: page, perPage, opt
+func (_m *API) GetFileInfos(page int, perPage int, opt *model.GetFileInfosOptions) ([]*model.FileInfo, *model.AppError) {
+	ret := _m.Called(page, perPage, opt)
+
+	var r0 []*model.FileInfo
+	if rf, ok := ret.Get(0).(func(int, int, *model.GetFileInfosOptions) []*model.FileInfo); ok {
+		r0 = rf(page, perPage, opt)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).([]*model.FileInfo)
+		}
+	}
+
+	var r1 *model.AppError
+	if rf, ok := ret.Get(1).(func(int, int, *model.GetFileInfosOptions) *model.AppError); ok {
+		r1 = rf(page, perPage, opt)
+	} else {
+		if ret.Get(1) != nil {
+			r1 = ret.Get(1).(*model.AppError)
+		}
+	}
+
+	return r0, r1
+}
+
 // GetFileLink provides a mock function with given fields: fileId
 func (_m *API) GetFileLink(fileId string) (string, *model.AppError) {
 	ret := _m.Called(fileId)