Weight in highres fix defaults to 1

[catboxanon]

Currently, if a LoRA is entered in the prompt as something like <lora:name:0.5>, and highres fix is enabled, if you enable plotting the weights it can be seen it jumps back to 1 in the highres fix pass. I've had to workaround this by entering <lora:name:0.5:hr=0.5>.

This is unrelated to #2 as I'm only entering the LoRA in the main prompt, and not the separate highres fix prompt.

I also don't think tests currently account for this which may explain how it got overlooked.

[cheald]

Ah, good catch. The hr weights weren't defaulting to their low-res equivalents correctly.

2bd6608 extracts the weight setup routine to its own easily-testable function, corrects the behavior, and adds tests.