BAM: Compact reads viewing mode

[iromeo]

For large coverage:

• show each read line 1 pixel height line, with mismatches info
• no spacer or 1x spacer between adjacent lines

[iromeo]

Fixed in https://github.com/JetBrains-Research/epigenome/commit/11de7ce58d6668dae63809ba1c1300c1ffef475f