Feature: Autosave and Undo/Redo

[0xi4o]

• Implements autosave in chatflow and agentflow canvas
• Implements undo/redo functionality in chatflow and agentflow canvas

[HenryHengZJ]

spotted 2 issues:

• strange black bar at top when refresh
• when open a new flow, it always autosaved first:

autosave.mp4

[HenryHengZJ]

Also something we discussed, nodes feel pretty laggy when there are quite a lot

• memoization of the nodes and inputs

[HenryHengZJ]

2 more bugs:

• as i type something and stop for seconds, it goes into autosave right, and it then unfocus the field, so I have to click the field again to make it focus, then i can start typing

autosavebug1.mp4

• open a canvas, modify some input field, wait for autosave to happens. now try pressing Ctrl + Z, it doesnt undo. However, it works when I click the Undo button

autosavebug2.mp4

[HenryHengZJ]

can play around with the background color of the toolbox in dark mode to see if white or some other dark colors suit better:

[0xi4o]

• open a canvas, modify some input field, wait for autosave to happens. now try pressing Ctrl + Z, it doesnt undo. However, it works when I click the Undo button
• canvas controls styling in dark mode
• as i type something and stop for seconds, it goes into autosave right, and it then unfocus the field, so I have to click the field again to make it focus, then i can start typing