Add: Optional implementation of std::optional for pre-C++17 compilers.

Sourced from https://github.com/akrzemi1/Optional, Boost Software License, Version 1.0.

Feature: NewGRF callback profiling (#7868)

Adds a console command newgrf_profile to collect some profiling data about NewGRF action 2 callbacks and produce a CSV file.

Add: [Win32] GDI engine for font glyph rendering as a replacement for including FreeType.

Building with FreeType is still possible and will take precedence over the GDI renderer, but
the project files don't include FreeType anymore by default. Combining GDI rendering with ICU
text layout is untested.

Codechange: Replace custom thread code with C++11 thread objects.

We assume a conforming C++11 compiler environment that has a valid <thread>-header.
Failure to run a real thread is handled gracefully.

Codechange: liblzma is called liblzma, how ever strange that might be

It is the only library we use that calls itself with 'lib' in the
name. This might be confusing, but with the arrival of cmake a lot
of these things are automated. And detection will find 'liblzma',
not 'lzma', like with 'lzo', 'zlib', ..

Change: Always build baseset metadata, instead of including it in the repo.

This adds a script and project files to generate these files within MSVC.

Codechange: [Blitter] Change DrawLine to be templated

This is remove per-pixel overheads due to use of the SetPixel virtual
method.
These overheads included:
* expensive virtual method call which prevents inlining
* palette lookup for every pixel
* branch on whether palette animation is enabled on every pixel

Regenerate project files.

Change: use vcpkg integration in Visual Studio

Removes the need for us to provide OpenTTD-useful package

Feature: Framerate display window (#6822)

Frame rate and various game loop/graphics timing measurements and graphs. Accessible via the Help menu, and can print some stats in the console via the fps command.

Change: [Win32] Use Uniscribe instead of ICU for text caret handling.

This removes the need for the ICU lib on Windows.

Add: [Win32] Text layout using the native Windows Uniscribe library.

Uniscribe is sometimes producing different results compared to ICU, especially
when RTL and LTR content is mixed. Comparing the results to other programs
(like editors or web browsers) leads me to believe that the result are at least
not worse than ICU and possibly better.

Add: 32bpp SSE2 blitter palette animator (#6795)

Create a new blitter mode: 32bpp-sse2-anim, which is 32bpp-anim + this.
32bpp-sse2-anim is now used by default where 32bpp-anim would have been.
Also use this with the 32bpp-sse4-anim blitter.

See issue #6469.

Change #6685: Replace Win32 music driver with one not depending on MCI

MCI MIDI is poorly supported on newer versions of Windows and can cause large
delays at the beginning of tracks.

The new driver is based on a from-scratch reader for Standard MIDI Files. This
should be re-usable in other music drivers too, and can allow for finer control
of playback in general.

It also provides a better framework for reading MIDI data from other formats
than just SMF.

Change: [Win32] Declare in the app manifest that all current Windows versions are natively supported.

The main effect of this is currently a proper OS version in the crashlog.