Use defined mcast addr for device groups instead of sharing emuation

[pcdiem]

Description:

Related issue (if applicable): fixes #8258

**** NOTE: This is a breaking change. This update changes the multicast address and port used by device groups. All devices using the device groups feature must be upgraded. ****

Use compile-time defined multicast address for device groups instead of sharing the emulation (SSDP) socket.

For DevGroupSend, ignore out share mask and always process locally.

Code size reductions.

Checklist:

• The pull request is done against the latest dev branch
• Only relevant files were touched
• Only one feature/fix was added per PR.
• The code change is tested and works on core Tasmota_core
• The code change is tested and works on core ESP32
• The code change pass travis tests. Your PR cannot be merged unless tests pass
• I accept the CLA.