GD-Storage: Implement Device, LeDevice, and ClassicDevice

* Implement abstractions for read, write and remove configs
* Device is the general layer for both LE and Classic
* ClassicDevice and LeDevice each allow interfacing with type specific
  properties
* Create storage::Serializable interface to allow cutsom defined
  serialization and deserialization
* Create hci/enum_helper.h to allow custom defined parsing of enum
  values

Bug: 157533831
Tag: #gd-refactor
Test: atest bluetooth_test_gd
Change-Id: I8d84a594d8d39c975651dd57b3fa361dd3b96ed4