Refactor attributes to reduce code duplication and improve maintainability.
* Add attribute base classes to provide common code.
* Add const where possible to functions and parameters.
* `NimBLECharacteristic::notify` no longer takes a `bool is_notification` parameter, instead `indicate()` should be called to send indications.
* `NimBLECharacteristic::indicate` now takes the same parameters as `notify`.
* `NimBLECharacteristicCallbacks` and `NimBLEDescriptorCallbacks` methods now take `const NimBLEConnInfo&` instead of non-const.
* `NimBLECharacteristic::onNotify` callback removed as unnecessary, the library does not call notify without app input.
* `NimBLERemoteCharacteristic::getRemoteService` now returns a `const NimBLERemoteService*` instead of non-const.
* Add NimBLEUUID constructor that takes a reference to `ble_uuid_any_t`.
* `NimBLERemoteService::getCharacteristics` now returns a `const std::vector<NimBLERemoteCharacteristic*>&` instead of non-const `std::vector<NimBLERemoteCharacteristic*>*`
* `NimBLERemoteService::getValue` now returns `NimBLEAttValue` instead of `std::string`
* `NimBLEService::getCharacteristics` now returns a `const std::vector<NimBLECharacteristic*>&` instead of a copy of std::vector<NimBLECharacteristic *>.
* Remove const requirement for NimBLEConnInfo parameter in callbacks.
Const is unnecessary as the data can't be changed by application code.
* Change NimBLERemoteCharacteristic::getRemoteService to return const pointer.
* msbFirst parameter has been removed from constructor as it was unnecessary,
caller should reverse the data first or call the new `reverseByteOrder` method after.
* `getNative` method replaced with `getBase` which returns a read-only pointer to the UUID size underlying.
* Added `reverseByteOrder` method, this will reverse the bytes of the UUID, which can be useful for advertising/logging.
* Added `getValue` method, which returns a read-only `uint8_t` pointer to the UUID value.
* Removed `m_valueSet` member variable, `bitSize()` can be used as a replacement.
* General code cleanup.
When retrieving attribute handles using the 128bit base version of a 16 bit UUID some devices will
report "not found". This will attempt to convert the UUID to the 16bit version and try again.
* Adds `to16()` method to NimBLEUUID.
* Sets macros to allow compiling when Central role is enabled and Observer disabled, or Peripheral enabled and Broadcaster disabled.
* Adds a macro definition for CONFIG_NIMBLE_CPP_IDF to enable different include paths/functionality for IDF / Arduino.
* Stores complete advertisement payload and only performs parsing on demand. The advertised data is no longer parsed automatically as it is discovered, instead it will be parsed to find only the data requested by the user application when it makes a call to do so. This saves processing time and approximately 2.4k in flash size, with the new methods listed below included.
Add more advertised device field methods:
* Adds haveAdvInterval/getAdvInterval - checks if the interval is advertised / gets the advertisement interval value.
* Adds haveConnParams/getMinInterval/getMaxInterval - checks if the parameters are advertised / get min value / get max value.
* Adds haveURI/getURI - checks if a URI is advertised / gets the URI data.
* Adds haveTargetAddress/getTargetAddressCount/getTargetAddress(index) - checks if a target address is present / gets a count of the addresses targeted / gets the address of the target at index.
This allows NimBLE options in menuconfig to reduce code size based on
the roles selected (scan/advertising/central/peripheral).
Significant code space can be saved by removing unnecessary roles for the application.
