[MM-26812] Add support for resumable file uploads (#15252)

* Implement AppendFile for FileBackend

* Split test into subtests

* [MM-26812] Add support for resumable file uploads (#15252)

* Implement UploadSession

* Implement UploadSessionStore

* Add error strings

* Implement resumable file uploads

* Add UploadType

* Fix retry layer tests

* Regenerate store layers

* Fix store error handling

* Use base for filename

* Prevent concurrent uploads on the same upload session

* Fix erroneus error string

* Improve error handling

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

* Fix translations

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

web/context.go

@@ -386,6 +386,18 @@ func (c *Context) RequireFileId() *Context {
 	return c
 }
 
+func (c *Context) RequireUploadId() *Context {
+	if c.Err != nil {
+		return c
+	}
+
+	if !model.IsValidId(c.Params.UploadId) {
+		c.SetInvalidUrlParam("upload_id")
+	}
+
+	return c
+}
+
 func (c *Context) RequireFilename() *Context {
 	if c.Err != nil {
 		return c