editor for viewing contract code

[tom2drum]

There could be multiple source codes for a single contract (30 and more in some cases) that are displayed now as snippets one below another. This makes exploring the code a little irritating and makes difficult to implement a good "search in files" functionality.

So, I think that would be better if we have a simple code editor for this (e.g VSCode has embeddable web version called Monaco Editor), where user can easily view source code and search through all files.

I drew some mockups just to show how I think this should look like. The yellow part (code viewer) could be taken from Monaco Editor npm package as it is, and the red parts (tabs and sidebar with file tree and search) are needed to be implemented from scratch.