Restructure remoteconfig HTTP content files

Reorganize and update lib-remoteconfig/http/content assets: remove many legacy per-module compressed JS header files and outdated status/layout files, add consolidated/static HTML and JS headers (default, dmx, rdm, rtc, showfile, time, static), and update central includes (content.h, includes.h), index (index.html.h, index.js.h) and styles. This brings new/merged UI pages and assets, cleans up obsolete files, and centralizes content delivery for the remoteconfig HTTP interface.

Author: vanvught