Add crf-search -v & auto-encode -v, -vv flag support

[alexheretic]

• Add crf-search -v flag to print per-sample results.
• Add auto-encode -v flag to print per-crf results, -vv to also print per-sample results.

$ ab-av1 auto-encode -i tmp.mp4 -vv
Encoding /home/alex/tmp/tmp.av1.mp4
- crf 32: Sample 1 (20%) vmaf 92.34 (cache)
- crf 32: Sample 2 (17%) vmaf 92.05 (cache)
- crf 32 VMAF 92.20 (19%) (cache)
- crf 19: Sample 1 (55%) vmaf 96.53 (cache)
- crf 19: Sample 2 (48%) vmaf 96.50
- crf 19 VMAF 96.51 (51%)
- crf 24: Sample 1 (40%) vmaf 95.22
- crf 24: Sample 2 (34%) vmaf 95.11
  00:00:00 crf 24 2/2 ############################################# (VMAF 95.17, size 37%)
⠈ 00:00:17 Encoding ################################-------------------- (41 fps, eta 16s)