Refactor NimBLEAddress - use NimBLE core representation.

[h2zero]

This simplifies the NimBLEAddress code by directly using the NimBLE core ble_addr_t type to hold the address and allows using NimBLE core functions and macros to replace code in some methods.

• Adds getBase method to access the base NimBLE address struct.
• Adds isNrpa method to test if an address is random non-resolvable.
• Adds isStatic method to test if an address is random static.
• Adds isPublic method to test if an address is a public address.
• Adds isNull methods to test if an address is NULL.
• equals method and == operator will now also test if the address types are the same.
• Code cleanup