Retain previous trajectory state when cancelling autoconversion

[interim17]

Time estimate or Size

tiny, less than 5 min

Problem

Closes #525

Solution

This issue was caused by having multiple websocket connections open during conversion, something @ascibisz fixed a while back.

So we can just stop clearing out the old trajectory when cancelling conversion and it should work fine.

[github-actions[bot]]

Coverage report

St.:grey_question:	Category	Percentage	Covered / Total
🟡	Statements	66.26%	644/972
🟡	Branches	65.73%	94/143
🔴	Functions	35.1%	86/245
🟡	Lines	64.65%	576/891

Test suite run success

104 tests passing in 7 suites.

Report generated by 🧪jest coverage report action from b5bec2a433c11bb2f54f1c9de2090d0dda40cf1b