This change ports SAE(Simultaneous Authentication of Equals)
feature from wpa_supplicant and makes it work with mbedtls
crypto APIs. Currently only group 19 is supported. A sample
SAE handshake is included in the testcase. Other minor
changes for DH groups are also included.
Move supplicant to idf and do following refactoring:
1. Make the folder structure consitent with supplicant upstream
2. Remove duplicated header files and minimize the public header files
3. Refactor for WiFi/supplicant interfaces