minor, provide --guess to ute-info command for interval guess work

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, refactor info mark() routine into mark_ssnp() and mark_scdl() coroutines after yielding the main mark work

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, implement --guess'ing for candles without start timestamp

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'cmd/info' into next

* cmd/info:
  minor, implement --guess'ing for candles without start timestamp
  minor, refactor info mark() routine into mark_ssnp() and mark_scdl() coroutines after yielding the main mark work
  minor, provide --guess to ute-info command for interval guess work