Make Wi-Fi mac more accessible (make wifi host and wpa supplicant pluggable and remove lwip tcpip stack dependency)

[amitv87]

There is real need to have a pluggable/open wifi host and wpa supplicant to run different tcpip stacks in BL wifi chips.

The sdk from Ai-Thinker is close to what I am looking for but the host and supplicant are still dependent on lwip tcpip stack.

The issue mentions the interfaces esp-idf has exposed to run different tcpip stack implementations. However only that is not enough, the host and supplicant layers should have no dependency on tcpip stack. Also the idf is not dependent on mbedtls for crypto required by the supplicant.

In short the wifi mac should be accessible in same way how the bt/ble controller is accessible over hci and hence any host implementation can be plugged in.