[FEATURE] - Add ability to use escaped characters to insert hexadecimal characters into DevJson commands

[ndorin]

Please test Essentials https://github.com/PepperDash/Essentials/releases/tag/v2.36.3-feature-add-escape-handling-for-devjson.1 to see if this feature works.

Non-printable characters will need to be double escaped:

power on\\r or power on\\x0D to send power on [0x0D]