Add location format attribute to Homie V5

[michcfr]

Hello,
What about adding to Homie V5 the location format attribute?

The location attribute would be defined with the same principle as the color attribute:
-location property format definition (as already discussed in a past thread):
"geo": would require latitude, longitude, altitude
"relative": would require X,Y,Z
"room": would require a string
-payload with comma separated
-supported with order of preference
....

Regards,
michcfr