Update Zigbee WebUI

[SteWers]

Description:

Update Zigbee WebUI

• refresh look of Zigbee WebUI
• some html fixes
• update DE language

Checklist:

• The pull request is done against the latest development branch
• Only relevant files were touched
• Only one feature/fix was added per PR and the code change compiles without warnings
• The code change is tested and works with Tasmota core ESP8266 V.2.7.8
• The code change is tested and works with Tasmota core ESP32 V.3.1.7
• I accept the CLA.

[s-hadinger]

Please provide screenshots before / after. It's hard to see from source what has been changed

[SteWers]

At init phase the table was broken:

after changes:

Appearance of the join phase. Before:

after:

[s-hadinger]

Ah ok thanks.