* changing dependencies from unity->cmock
* added component.mk and Makefile.projbuild
* ignore test dir in gen_esp_err_to_name.py
* added some brief introduction of CMock in IDF
Move existing core dump files into espcoredump component folder
Add KConfig, linker.lf, make and CMakeList.txt for new component
Existing functionality separated into core_dump_common, core_dump_flash, core_dump_uart
Update test_core_dump.c and make files to link it as unit test
Update according to review:
Move target and RTOS related functionality into separated file (core_dump_port.c).