Added support for Shelly BLU Wall Switch 4 via BTHome integration hold (released)

[rhammeran]

Blueprint Checklist

• You viewed the README and conformed to the naming conventions
• You ordered the actions as stated in the README action order
• All filenames are lowercase and uses '-' for spaces and not '_' while using {service-name}-{switch-name-or-type}.yaml format
• Images are png
• Image backgrounds are transparent and is cropped to the device boundries
• Images has a maximum width of 800px and maximum height of 500px
• There are no missing buttons or actions
• Your integration/service is running on the latest version
• You have tested your blueprints and made sure each button and action works

Zigbee2MQTT

• (older devices) You have ensured legacy is off/false for the device in the Z2M devices Settings (specific) page and that your actions matches those with legacy off?

[Sian-Lee-SA]

released should be named hold (released)

[Sian-Lee-SA]

You changed it for the first button but not the other 3 😉