A couple of enhacement suggestions

Hi,

First of all, thank you for this great project - it's really helpful and helps to save a lot of time.

Today I used the interactive BOM during assembly of two rather large PCBs (~350 BOM entries each). Based on my first impressions, I came up with a list of suggestions that could make manual assembly process a bit smoother. I just wanted to know if there's any chance that these could be implemented in the future versions:

• Add an option or filter syntax to search only specific columns (https://github.com/openscopeproject/InteractiveHtmlBom/issues/167 might be related?). Suppose you only want to see 120 Ohm resistors - when you search for 120 all the 1206 footprints will be selected too. Searching only the values is especially useful if you don't follow any strict placement order and just grab one bag of parts after another in random order and then just search the BOM for whatever fell into your hands.
• Add a keyboard shortcut to focus on the element list. When you want to filter the list, you can press Alt+F to focus on the filter field and search for something. As far as I know, there is no way to bring the focus back to the element list other than by using your mouse.
• Add an option to sort elements by their proximity instead of sorting by reference - this could make the placement order more natural.
• Make it possible to center the PCB preview on the currently selected element - useful when the viewport is too small to show the entire PCB.

This was my first time using this tool, so I suppose some of the features I mentioned might already exist, but I could have just missed them. In any case, if you think that any of these are worth having, I could try (I'm not very good with Python) to implement some of them and open a PR.

Thanks

Start by reviewing the four requested behaviors in this issue and the existing interactive BOM controls for filtering, focus, sorting, and PCB centering. The issue does not name files, tests, or entry points, and completion criteria for the individual suggestions are not defined; determine which proposal is accepted before starting implementation.