Feature: Add the ability to clone an area with structures

[StanislavShamrai]

Motivation / Problem

@StanislavShamrai wants to automate a process by creating a new object using existing logic.

Description

You can build larger paths by simply copying and pasting some of the existing intersections and paths. You can rotate an area by inserting it at a different angle.

Limitations

This was created for railroad tracks, tunnels, and bridges, but the same behavior may be added for other types of tracks and structures in the future.

Checklist for review

• This PR touches english.txt or translations? Check the guidelines
• This PR affects the NewGRF API? (label 'needs review: NewGRF')
  • newgrf_debug_data.h may need updating.
  • PR must be added to API tracker

example: clone-area.webm

[PeterN]

The list of commits looks a bit messy, did you mean to squash it again?

Additionally there are a lot of seemingly unrelated changes into table/sprites.h which might be better in a separate PR?