Codechange: remove C-style memory management

[rubidium42]

Motivation / Problem

OpenTTD has been a C++ application for years and most code is using C++ memory management, except a few stragglers.

These stragglers are anything using MallocT, CallocT, ReallocT and most uses of free except when data is coming from external APIs.

Description

Implemented:

• Codechange: use std::vector over ReallocT for dirty blocks #13331: usage of ReallocT for dirty blocks
• Codechange: manage the ParagraphLayouter's buffer with std::unique_ptr #13571: usage of MallocT for ParagraphLayouter's buffer
• Codechange: use std::allocator over malloc/free for Squirrel memory management #13632: usage of malloc by ScriptAllocator
• Codechange: remove C-style memory management from pools #13640: usage of MallocT/CallocT by pool
• Codechange: remove ZeroedMemoryAllocator #13644: usage of ZeroedMemoryAllocator by Window
• Codechange: remove SimpleSpriteAllocator #13646: usage of MallocT by SimpleSpriteAllocator; used in OpenGL and unit test

Limitations

Waiting for the PRs to get merged before the includes and unused code can finally be actually removed.

Checklist for review

Some things are not automated, and forgotten often. This list is a reminder for the reviewers.

• The bug fix is important enough to be backported? (label: 'backport requested')
• This PR touches english.txt or translations? Check the guidelines
• This PR affects the save game format? (label 'savegame upgrade')
• This PR affects the GS/AI API? (label 'needs review: Script API')
  • ai_changelog.hpp, game_changelog.hpp need updating.
  • The compatibility wrappers (compat_*.nut) need updating.
• This PR affects the NewGRF API? (label 'needs review: NewGRF')
  • newgrf_debug_data.h may need updating.
  • PR must be added to API tracker

[TrueBrain]

Time for some cake!