Add VT sequence: DECSCLM - Scrolling Mode #1204
Description
We currently only implement fast mode, but it might make sense to also implement smooth (slow) mode.
This mode only affects adding new lines at a slow rate, but - in modern age - we could correlate that feature with smooth scrolling (of new lines to be added), see #145.
One open question I am having is how long the linefeed should wait until resuming terminal I/O processing.
How to implement
One design idea I am having in my mind is, to actually suspend processing for N msecs on received linefeeds, if slow scrolling mode is enabled. This should effectively also suspend reading from the TTY to avoid flooding the internal buffers.