Support terminal resizing signals

[taramk]

You can run into display issues if you resize the window, particularly in micro.

Some highlighted text not showing up, here:

Paste some text into the micro editor, and click a line to highlight it. Some characters on the line below the highlighted text are obscured, almost like it's using the previous terminal window's dimensions.

Also, if you resize the window smaller and then bigger again, the text gets cut off like below:

[progrium]

We need to patch os/signal in the Go standard library since there is no support for signals in WASM or WASI. We tried doing a crazy link-time replacement idea, but it didn't work and darkarts didn't seem to support it, so we'll just have to patch the standard library source since we're building it anyway.