Hello Team,

Description:

As per issue #1240, this PR removes major non-hardware dependent compilation variables from ZgatewayBT.ino.

To achieve this, the following changes have been made:

• Move variable minRssi in config_BT.h,
• Create a struct (BTConfig_s) for BT configuration data,
• Create a default config for BTConfig_s (BTConfig_default) based on defines,
• Create a global variable (BTConfig) to hold live BT configuration data and initialize it,
• Move global variables bleConnect, BLEscanBeforeConnect, BLEinterval, PublishOnlySensors, hassPresence, minRssi into struct BTConfig_s,
• Add presenceTopic into BTConfig_s,
• Move MQTTDecodeTopic as extDecoderTopic into BTConfig_s,
• Move UseExtDecoder, BLE_FILTER_CONNECTABLE, pubKnownBLEServiceData, pubUnknownBLEServiceData, pubBLEManufacturerData, pubUnknownBLEManufacturerData, pubBLEServiceUUID, useBeaconUuidForTopic, `useBeaconUuidForPresence as runtime var into BTConfig_s

Also compilation variable AttemptBLECOnnect has been renamed AttemptBLEConnect, which could be A BREAKING CHANGE.
And compilation variable ServicedataMinLength has been removed (unused).

The next steps are:

1. Provide the ability to modify those configurations with mqtt payloads on MQTTtoBT topic,
2. Review White/Black-lists to handle "wildcard" mac adresses/uuid (point raised in issues Ibeacons with random MAC addresses #1139, iBeacon: Flag to use UUID in topic or presence (and fixes) #1226 and PR Basic whitelisting/blacklisting support for ZgatewayRF #919 for ZgatewayRF) and add a parameter to disable black/white-listing (point raised in issue BLE Whitelist. #331 and PR Add support to disable/enable white list control #615),
3. Persist configuration change in SPIFFS instead of having to retain the configuration in the Broker.

Tell me if this is going the right way for you.

Bad

Checklist:

• The pull request is done against the latest development branch
• Only one feature/fix was added per PR and the code change compiles without warnings
• I accept the DCO.