tt_RU: Fix orthographic mistakes in day and abday sections [BZ #24296]

This commit fixes some errors and converts all weekday names to lowercase.
The content is synchronized with CLDR-34 now, but trailing dots are removed
from abday values in order to maintain consistency with the previous values
and with many other locales which do the same.

	[BZ #24296]
	* localedata/locales/tt_RU (day): Update from CLDR-34, fix errors.
	(abday): Likewise, but remove the trailing dots.