alternatecalendar: Add Chinese lunar calendar system support

The traditional Chinese calendar (also known as the Agricultural
Calendar is a lunisolar calendar which identifies years, months,
and days according to astronomical phenomena. In China, it is defined
by the Chinese national standard GB/T 33661–2017, "Calculation and
Promulgation of the Chinese Calendar", issued by the Standardization
Administration of China on May 12, 2017.

The plugin is adapted from https://github.com/BLumia/pineapple-calendar



Co-authored-by: Gary Wang <wzc782970009@gmail.com>

FEATURE: 429892
FIXED-IN: 5.26