compare_cts_reports: support `ignore_abi` for csv report

Also support ignoring test ABIs while loading parsed csv
reports.

Bug: 315073470
Test: ./compare_cts_reports.py \
        -f report_dir_1 -f report_dir_2 \
	--mode 2 --output-dir output --ignore-abi
Change-Id: I23578fd5a3e901b2872010b7a17d6cc7ad273fe9
2 files changed