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
1. separate rom include files and linkscript to esp_rom
2. modefiy "include rom/xxx.h" to "include esp32/rom/xxx.h"
3. Forward compatible
4. update mqtt
* Move smartconfig to its component directory, it should be possible to override
this as whole component
* Fix few header includes related to lwIP networking stack
Signed-off-by: Mahavir Jain <mahavir@espressif.com>
