wifi: Implement chip mode combinations

This is pretty hardcoded for now. We expose 2 chip modes:
1. STA mode: 1 STA and 1 P2P or NAN iface.
2. AP mode: 1 AP iface.

Implement the chip mode configuration related HIDL methods in
WifiChip and integrate WifiModeController. These is some change in the
order of calls invoked within the implementation to accomodate the
firmware reload:
a. Since the legacy HAL needs to reinitialized after
firmware reload, we can no longer do this in IWifi.start().
So, we'll defer this to IWifiChip.configureChip() now.
b. Refactor IWifi.startInternal() and IWifi.stopInternal() to pull
out the actual implementation into a separate helper functions and
let it invoke the required callbacks.

Bug: 31997422
Bug: 32018162
Test: Compiles
Change-Id: I461687d7ee92398bc47321e1baca609db65c7991