Markets to JS

This MR converts the individual markets from a TW file to a DOM node. Sorry for the size. Many things happen in one passage now: selecting a market, viewing the slave in it, buying them, and moving to inseminate/brand etc. Less globals to worry about, and it will be handy to just grab a node.

Very few user facing improvements this time. Custom husk slave I was able to whiten selected options and added the ability to choose nationality from a list.

This MR did not change Custom Slave, and I just realized I still need to convert elite slave as well.

I also did not change the bulk slave purchase system in this mr, but may improve it in the future.

@svornost and preg let me know what you think, plenty of room for improvement here.

edit: over 20 tws removed, which is nice.