* [Cellular] Add cellulr lib submodule and demo app
* [Cellular] Fix memory violation in transport layer and add using LoggingPrintf
* Update FreeRTOS Cellular Interface
* Change the mbedtls usage in FreeRTOS-Plus
* [Cellular] Fix missing spell
* [Cellular] Add manifest.yml
* Fix missing spell
* Update manifest.yml
* [Cellular] Add integration test
* Modify the demo log level to LOG_INFO
* Update cellular interface
* The modification of the folder structure for cellular library
* Rename the naming of demo
* Adjust the location of using_mbedtls and socket_wrapper
* Adjust project setting for relocating using_mbedtls and socket_wrapper
* Turn off PSM mode
* Add start marker for CI validation.
* The modification for mbedtls platform send/recv function for cellular
* Change the project file due to the changes of mbedtls platform send/recv function for cellular
* Fix missing newline and remove unused file
* Add missing configuration.
* Make cellular and freertos tcp plus use the same transport implementation
* Add comment for the macro MBEDTLS_SSL_SEND and MBEDTLS_SSL_RECV
* Make changes from the github comment.
