Improve initialization process for NimBLE client

Rename setupAndStartBleScans to setupBleScans since it only
configures the BLE scanning.

Create new internal function to start BLE scans that gets called
from the begin() method.

keepAlive doesn't need to be called on init to start the scanning.
It can be used to re-start in case of errors as documented.

src/NimBleClient.cpp

@@ -2,19 +2,42 @@
 
 void NimBleClient::begin(BleClientCallback* callback) {
     _callback = callback;
-    setupAndStartBleScans();
+    setupBleScans();
+    startBleScans();
 }
 
 void NimBleClient::keepAlive() {
     // If an error occurs that stops the scan, it will be restarted here.
     if (!_bleScan->isScanning()) {
         // Start scan with: duration = 0 seconds(forever), no scan end callback,
         // not a continuation of a previous scan.
-        _bleScan->start(0, nullptr, false);
+        startBleScans();
     }
 }
 
-void NimBleClient::setupAndStartBleScans() {
+
+void NimBleClient::onResult(NimBLEAdvertisedDevice* advertisedDevice) {
+    if (!advertisedDevice->haveManufacturerData()) {
+        return;
+    }
+
+    // MAC address contains 6 bytes of MAC address (in reversed order)
+    // (Note: advertisedDevice->getAddress().toString() seems broken)
+    const uint8_t* bleMACAddress = advertisedDevice->getAddress().getNative();
+    std::string address;
+    for (int i = 5; i >= 0; i--) {
+        address.push_back(static_cast<char>(bleMACAddress[i]));
+    }
+
+    std::string name = advertisedDevice->haveName()
+                           ? advertisedDevice->getName()
+                           : "UNDEFINED";
+    std::string manufacturerData = advertisedDevice->getManufacturerData();
+
+    _callback->onAdvertisementReceived(address, name, manufacturerData);
+}
+
+void NimBleClient::setupBleScans() {
     // CONFIG_BTDM_SCAN_DUPL_TYPE_DATA_DEVICE (2)
     // Filter by address and data, advertisements from the same address will be
     // reported only once, except if the data in the advertisement has changed,
@@ -37,23 +60,8 @@ void NimBleClient::setupAndStartBleScans() {
     _bleScan->setMaxResults(0);
 }
 
-void NimBleClient::onResult(NimBLEAdvertisedDevice* advertisedDevice) {
-    if (!advertisedDevice->haveManufacturerData()) {
-        return;
-    }
-
-    // MAC address contains 6 bytes of MAC address (in reversed order)
-    // (Note: advertisedDevice->getAddress().toString() seems broken)
-    const uint8_t* bleMACAddress = advertisedDevice->getAddress().getNative();
-    std::string address;
-    for (int i = 5; i >= 0; i--) {
-        address.push_back(static_cast<char>(bleMACAddress[i]));
-    }
-
-    std::string name = advertisedDevice->haveName()
-                           ? advertisedDevice->getName()
-                           : "UNDEFINED";
-    std::string manufacturerData = advertisedDevice->getManufacturerData();
-
-    _callback->onAdvertisementReceived(address, name, manufacturerData);
+void NimBleClient::startBleScans() {
+    // Start scan with: duration = 0 seconds(forever), no scan end callback,
+    // not a continuation of a previous scan.
+    _bleScan->start(0, nullptr, false);
 }

src/NimBleClient.h

@@ -15,7 +15,8 @@ class __attribute__((unused)) NimBleClient
   private:
     NimBLEScan* _bleScan;
     BleClientCallback* _callback;
-    void setupAndStartBleScans();
+    void setupBleScans();
+    void startBleScans();
     void onResult(NimBLEAdvertisedDevice* advertisedDevice) override;
 };
 

src/Sensirion_upt_ble_auto_detection.cpp

@@ -6,7 +6,6 @@ const int COMPANY_ID_FILTER = 54534;
 void SensiScan::begin() {
     _bleClient = new NimBleClient();
     _bleClient->begin(this);
-    _bleClient->keepAlive();
 }
 
 __attribute__((unused)) void SensiScan::getScanResults(