**KateModeManager::updateFileType():**
* Validate modes of **katemoderc**: In the same way as in D25389, the file **katemoderc** may contain invalid modes due to custom XML files that are deleted or renamed. Therefore, the existing modes are now verified and then the configuration of the **katemoderc** file is overwritten.
* Prevent the **Normal** mode from being duplicated if the file **katemoderc** exists.
* Modes with empty names are skipped. It's understood that the name of a mode shouldn't be empty, since it acts as a unique identifier.
* Update the list of modes in the status bar menu (class KateModeMenuList) by calling `updateFileType()`. The menu uses the `KateFileType` objects to do a file extension search, so it's necessary. To do this, the `KateModeMenuList::reloadAll()` function is added, which updates the data model of the menu.