Alignment for overview ruler decorations on the same line is off

[meganrogge]

The alignment seems off with these:

Also blue/right is being drawn largest?

Originally posted by @Tyriar in #3676 (comment)

[Tyriar]

Current:

Expected:

[Tyriar]

Also monaco does 2px tall for full and 6px for others, we're at 3px and 7px currently