tt_RU: Fix orthographic mistakes in mon and abmon sections [BZ #24369]

This commit fixes some errors and converts all month names to lowercase.
The content is synchronized with CLDR-35.1 now but trailing dots are
removed from abmon values in order to maintain consistency with the
previous values and with many other locales which do the same.

	[BZ #24369]
	* localedata/locales/tt_RU (mon): Update from CLDR-35.1, fix errors.
	(abmon): Likewise, but remove the trailing dots.