Race condtion:
* First command timeouted, but the reply came just after evaluation and
set signal variable to GOT_LINE
* Second command should timeout too, but a consistency check validates
that it timeouted and at the same time GOT_LINE (from previous step) and
throws an exception
STR:
* Revert change in esp_modem_dte.cpp
* Run TEST_CASE("DTE command races", "[esp_modem]")
Closes https://github.com/espressif/esp-protocols/issues/110
reworks to clear shared_ptr<> of both command and data terminals
and having DTE own it. When we swith to CMUX mode the ownership is transfered to CMux terminal
