[Bug Report] The links is so blurry unless set `this.graph.config.links_ontop` to true, on HiDPI screens.

[cesaryuan]

The links is so blurry unless we change if (this.graph.config.links_ontop) to if(true) in file src\litegraph.js line 7938.

litegraph.js/src/litegraph.js

Line 7938 in 0555a2f

if (this.graph.config.links_ontop) {

Reproduce steps:

1. git clone https://github.com/jagenjo/litegraph.js.git
2. cd litegraph.js
3. npm install
4. node utils/server.js
5. Open Copy Paste demo.
6. We can see that the links is blurry.
7. Change if (this.graph.config.links_ontop) to if(true) in file src\litegraph.js line 7938.
8. Reload page and Open Copy Paste demo.
9. We can see that the links is clear.

Before vs After

Upate: I just found the problem where it is. This is because we only scale the foreground canvas, but not the background canvas.