0.21.0.985 RC

- NoChatsText: Now you need to put 2 newlines after the bold title in the beginning of the string (No chats to show in English), instead of 1. You can also use newlines by yourself freely, if needed in this string.
- When selecting a localization, which was previously used, it will be synced before the language gets applie to the UI (this fixes "Localization file is empty" for Italian language)
- Added ToolsStringSectionMain, ToolsStringSectionUrl, ToolsStringSectionFormat, ToolsStringSectionRelativeDate, ToolsStringSectionPlural, ToolsStringSectionSimpleFormatted, `ToolsStringSectionSimple: sections in localization strings list
- Added TdlibLogClearEmpty, TdlibLogClearOk, TdlibLogClearFail: toast notifications when clearing TDLib log
- Better number & file size formatting in Spanish
- Fixed: After using "Paste original" & pressing "Save & Exit", string is not saved