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).
