Add --color command line argument to control colored console output

[Calinou]

• Follow-up to Add colors to the command-line help #36252.

This also adds support for the NO_COLOR environment variable, and harmonizes checks for colored console output by using a unique Engine method.

• auto (default): Only color if output is a TTY (interactive session). Color is disabled if the NO_COLOR environment variable is set to a non-empty string, as per https://no-color.org.
• always: Always color, even if output is a file or is non-interactive (useful for continuous integration, which is non-interactive). This also bypasses NO_COLOR as per its specification.
• never: Never color command line output.

Preview

[Calinou]

I've tried to fix the build on Windows, but am not sure how to fix the heap-use-after-free in the Linux build:

==7218==ERROR: AddressSanitizer: heap-use-after-free on address 0x612000009650 at pc 0x5577491682f7 bp 0x7fff032db4d0 sp 0x7fff032db4c0
READ of size 8 at 0x612000009650 thread T0
    #0 0x5577491682f6 in UnixTerminalLogger::log_error(char const*, char const*, int, char const*, char const*, bool, Logger::ErrorType) (/home/runner/work/godot/godot/bin/godot.linuxbsd.editor.dev.double.x86_64.san+0x45dfb2f6)
    #1 0x55775ada11f3 in CompositeLogger::log_error(char const*, char const*, int, char const*, char const*, bool, Logger::ErrorType) (/home/runner/work/godot/godot/bin/godot.linuxbsd.editor.dev.double.x86_64.san+0x57a341f3)
    #2 0x55775a71fe05 in OS::print_error(char const*, char const*, int, char const*, char const*, bool, Logger::ErrorType) (/home/runner/work/godot/godot/bin/godot.linuxbsd.editor.dev.double.x86_64.san+0x573b2e05)
    #3 0x55775c1f4cf9 in _err_print_error(char const*, char const*, int, char const*, char const*, bool, ErrorHandlerType) (/home/runner/work/godot/godot/bin/godot.linuxbsd.editor.dev.double.x86_64.san+0x58e87cf9)
    #4 0x55775c1f49ab in _err_print_error(char const*, char const*, int, char const*, bool, ErrorHandlerType) (/home/runner/work/godot/godot/bin/godot.linuxbsd.editor.dev.double.x86_64.san+0x58e879ab)
    #5 0x55775bf1c1ca in ObjectDB::cleanup() (/home/runner/work/godot/godot/bin/godot.linuxbsd.editor.dev.double.x86_64.san+0x58baf1ca)
    #6 0x55775a5520bd in unregister_core_types() (/home/runner/work/godot/godot/bin/godot.linuxbsd.editor.dev.double.x86_64.san+0x571e50bd)
    #7 0x55773fd09e89 in Main::test_cleanup() (/home/runner/work/godot/godot/bin/godot.linuxbsd.editor.dev.double.x86_64.san+0x3c99ce89)
    #8 0x55773fd0a29d in Main::test_entrypoint(int, char**, bool&) (/home/runner/work/godot/godot/bin/godot.linuxbsd.editor.dev.double.x86_64.san+0x3c99d29d)
    #9 0x55773fa8be31 in main (/home/runner/work/godot/godot/bin/godot.linuxbsd.editor.dev.double.x86_64.san+0x3c71ee31)
    #10 0x7f861c5b0082 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x24082)
    #11 0x55773fa8bbad in _start (/home/runner/work/godot/godot/bin/godot.linuxbsd.editor.dev.double.x86_64.san+0x3c71ebad)

0x612000009650 is located 16 bytes inside of 264-byte region [0x612000009640,0x612000009748)
freed by thread T0 here:
    #0 0x7f861d37040f in __interceptor_free ../../../../src/libsanitizer/asan/asan_malloc_linux.cc:122
    #1 0x55775a71a7c8 in Memory::free_static(void*, bool) (/home/runner/work/godot/godot/bin/godot.linuxbsd.editor.dev.double.x86_64.san+0x573ad7c8)
    #2 0x55773fd8c5c4 in void memdelete<Engine>(Engine*) (/home/runner/work/godot/godot/bin/godot.linuxbsd.editor.dev.double.x86_64.san+0x3ca1f5c4)
    #3 0x55773fd09e70 in Main::test_cleanup() (/home/runner/work/godot/godot/bin/godot.linuxbsd.editor.dev.double.x86_64.san+0x3c99ce70)
    #4 0x55773fd0a29d in Main::test_entrypoint(int, char**, bool&) (/home/runner/work/godot/godot/bin/godot.linuxbsd.editor.dev.double.x86_64.san+0x3c99d29d)
    #5 0x55773fa8be31 in main (/home/runner/work/godot/godot/bin/godot.linuxbsd.editor.dev.double.x86_64.san+0x3c71ee31)
    #6 0x7f861c5b0082 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x24082)

previously allocated by thread T0 here:
    #0 0x7f861d370808 in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cc:144
    #1 0x55775a71976d in Memory::alloc_static(unsigned long, bool) (/home/runner/work/godot/godot/bin/godot.linuxbsd.editor.dev.double.x86_64.san+0x573ac76d)
    #2 0x55775a71967e in operator new(unsigned long, char const*) (/home/runner/work/godot/godot/bin/godot.linuxbsd.editor.dev.double.x86_64.san+0x573ac67e)
    #3 0x55773fd079a1 in Main::test_setup() (/home/runner/work/godot/godot/bin/godot.linuxbsd.editor.dev.double.x86_64.san+0x3c99a9a1)
    #4 0x55773fd0a284 in Main::test_entrypoint(int, char**, bool&) (/home/runner/work/godot/godot/bin/godot.linuxbsd.editor.dev.double.x86_64.san+0x3c99d284)
    #5 0x55773fa8be31 in main (/home/runner/work/godot/godot/bin/godot.linuxbsd.editor.dev.double.x86_64.san+0x3c71ee31)
    #6 0x7f861c5b0082 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x24082)

The problematic line is https://github.com/Calinou/godot/blob/4dd89b440234c8e1b4d7e6da748d20d859049f0f/drivers/unix/os_unix.cpp#L794. I'm just not sure how to avoid having to query the Engine singleton here, while keeping the solution as local as possible.