Add support for MJGDYK01YL dimmer variation to miot_ylkg0xyl and miot_ylxx0xyl_pair

[vanzi11a]

Motivation
MJGDYK01YL is a dimmer that's shipped with Xiaomi Smart Monitor Light Bar 1S.

There're several instructions around to flash this device with Tasmota[1] or ESPHome, but none of them considers making a remote work. I decided I don't want to lose a remote, poked the device using your components, and turns out it's nearly identical to other Yeelight dimmers, only having a different product_id.
Thus, with minimal changes to miot_ylkg0xyl I was able to make it work with my lamp. I have an end-to-end working ESPHome config that is currently targeting my fork: https://github.com/vanzi11a/esphome-xiaomi_monitor_light_bar_s1

Using miot_ylxx0xyl_pair to extract bindkey also worked, but it took about three attempts to get past step 3.

Changes

• Add MJGDYK01YL as a variation of ylkg0xyl with a different product_id