This is a specialized container class to hold BLE attribute values.
- Removes the use of std::string previously used to store the values.
- Allows for setting/getting/notifying values from std::string, std::vector<uint8_t>, Arduino String, const char*, and uint8_t buffers.
- Has operators retrieve the value as std::string, Arduino String, std::vector<uint8_t>, uint8_t* or char pointers.
- Includes iterators and subscript/random access operator.
- Introduces a max length parameter to the creation of server characteristics/descriptors to limit the size of the memory footprint.
- Nearly Seamless integration with existing code.
- Adds a config option to enable/disable timestamp storage when the value is updated.
- Adds a config option to specify the initial size of the value container if not specified in the constructor.
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.
