* General code cleanup
* `NimBLEExtAdvertisement` : All functions that set data now return `bool`, true = success.
* Added new method, `NimBLEExtAdvertisement::removeData`, which will remove the data of the specified type from the advertisement.
* Added new method, `NimBLEExtAdvertisement::addServiceUUID`, which will append to the service uuids advertised.
* Added new method, `NimBLEExtAdvertisement::removeServiceUUID`, which will remove the service from the uuids advertised.
* Added new method, `NimBLEExtAdvertisement::removeServices`, which will remove all service uuids advertised.
* Added overloads for `NimBLEExtAdvertisement::setServiceData` with the parameters `const NimBLEUUID& uuid, const uint8_t* data, size_t length` and
`const NimBLEUUID& uuid, const std::vector<uint8_t>& data`.
* Added new method, `NimBLEExtAdvertisement::getDataLocation`, which returns the location in the advertisment data of the type requested in parameter `uint8_t type`.
* Added new method, `toString` which returns a Hex string representation of the advertisement data.
Adds support for advertising and connections with coded/2M PHY's.
Adds new classes `NimBLEExtAdvertising` and `NimBLEExtAdvertisement`.
When extended advertising is enabled the original advertising classes become unavailable and the new classes must be used.
Changed some return values for advertising methods for consistency with the new classes methods.
