Add new mode, add RAX10 and RAX50 to supported devices list

[jlinktu]

Added Nighthawk AX6 / RAX50 V1.0.12.120_2.0.83 to confirmed device - firmware section.

[jlinktu]

Added a fourth mode to support devices that expect the following payload format:

struct payload {
    char signature[0x10];
    char mac[0x10];
    char username[0x10];
    char password[0x88];
    char reserved[0x40];
};

The Blowfish cipher uses the sha256 hash of the http password (like mode 2) and in addition uses the hash as password in the payload.

[bkerler]

Thanks :)