[TCSACR-10] Add new methods

[TCSACR-10] Add new methods

1. Change ConnectionProfile.State --> ConnectionProfile.GetState(AddressFamily family)
2. Add PrefixLength to IAddressInformation
3. Add DnsConfigType to IAddressInformation
4. Add GetStatistics() and ResetStatistics() to ConnectionManager
5. Add Refresh() to ConnectionProfile
6. Add PdnType and RoamPdnType to CellularProfile
7. Add GetAllIPv6Addresses() to ConnectionManager
8. Change the return type of ConnectionManager.GetIPAddress()

Change-Id: Ie6cab571c3f7ed080dee63874fec78bb8722b431
Signed-off-by: cheoleun <chleun.moon@samsung.com>