Detect changes in Jumuaas

[hammady]

@fayez-nazzal please note the schema change. For each masjid, a new optional boolean denotes if jumaas have changed for this masjid:

{
    "max_jumaas": 5,
    "masjids": {
        "MNNexus": {
            "iqamas": {},
            "jumas": [],
            "jumas_changed": true
        }
   }
}