Fix: Memory leak in ICUParagraphLayout::NextLine() (#11895)

This function calls icu::BreakIterator::createLineInstance() but does not clean up after it.

Instead use a static instance that is cloned (for thread-safety) and deleted as necessary.

Codechange: Store text run positions in vector of points.

This simplifies the interlaced vector of x/y positions.

Codechange: automatic adding of _t to (u)int types, and WChar to char32_t

for i in `find src -type f|grep -v 3rdparty/fmt|grep -v 3rdparty/catch2|grep -v 3rdparty/opengl|grep -v stdafx.h`; do sed 's/uint16& /uint16 \&/g;s/int8\([ >*),;[]\)/int8_t\1/g;s/int16\([ >*),;[]\)/int16_t\1/g;s/int32\([ >*),;[]\)/int32_t\1/g;s/int64\([ >*),;[]\)/int64_t\1/g;s/ uint32(/ uint32_t(/g;s/_uint8_t/_uint8/;s/Uint8_t/Uint8/;s/ft_int64_t/ft_int64/g;s/uint64$/uint64_t/;s/WChar/char32_t/g;s/char32_t char32_t/char32_t WChar/' -i $i; done

Codechange: Use unique_ptr for text layout font mapping.

This must stay a pointer as the value passed to other structures.

Codechange: C++-ify the Layouter and related functions

They all now access a std::string_view, instead of a "const char *"
or std::string (in some cases).

Additionally, GetCharAtPosition and friends now return an index
instead of a "const char *", as it makes for a more clear interface.

Change: include fmt.h C++ headers in stdafx.h

This to prevent compilation issues between runs with and without precompiled
headers. Also remove the headers from the rest of the code base as they are
not needed there anymore, although they do relatively little harm.

Feature: drop ICU-lx in favour of directly interfacing with harfbuzz

This means we have RTL support again with ICU 58+. It makes use of:
- ICU for bidi-itemization
- ICU for script-itemization
- OpenTTD for style-itemization
- harfbuzz for shaping

Codechange: Improve LineCache queries (#9417)

Adds the support to query the linecache without copying the string.
This uses a custom transparent comparator in conjunction with
a query type using a std::string_view.

Codechange: Store text layout runs directly as values in a std::vector instead of heap allocated.

This reduces memory allocations and heap fragmentation.

Codechange: ICU_LAYOUT is in reality ICU_LX (according to their CMake files)

By naming it in a different way, things get a bit confusing.
Especially if we are switching to CMake, which autodetects these
things, we need to use the name the authors of ICU gave it; not
our interpertation of that name.

Codechange: Make std::stack use std::vector container in string formatting/drawing. (#7305)

This is a very minor performance increase which can add up during operations such
as sorting. Performance impact my be platform/compiler dependent.

Add: {PUSH_COLOUR} and {POP_COLOUR} control codes to handle switching colours. (#6737)

This replaces the internal SCC_PREVIOUS_COLOUR swap.

(svn r26017) -Change: allow the fallback and ICU layouter to exist in unison
-Fix [FS#5711]: crash when the ICU layouter thinks a font is corrupted