Add build flags to output of lmms --version

[SpomJ]

Adds WANT, LMMS_HAVE and LMMS_DEBUG flags the package was compiled with to the output of lmms --version

[JohannesLorenz]

Note, this could be tested in CI after I merge #7427 .

[tresf]

As @SpomJ described on Discord, this PR was partially inspired by ffmpeg's behavior:

ffmpeg --version

ffmpeg version 7.1.1 Copyright (c) 2000-2025 the FFmpeg developers
  built with Apple clang version 16.0.0 (clang-1600.0.26.6)
  configuration: --prefix=/opt/homebrew/Cellar/ffmpeg/7.1.1_1 --enable-shared
--enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags='-Wl,-ld_classic'
--enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libaribb24
--enable-libbluray --enable-libdav1d --enable-libharfbuzz --enable-libjxl --enable-libmp3lame
--enable-libopus --enable-librav1e --enable-librist --enable-librubberband --enable-libsnappy
--enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtesseract --enable-libtheora
--enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp
--enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma
--enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass
--enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libspeex
--enable-libsoxr --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack
--enable-videotoolbox --enable-audiotoolbox --enable-neon

  libavutil      59. 39.100 / 59. 39.100
  libavcodec     61. 19.101 / 61. 19.101
  libavformat    61.  7.100 / 61.  7.100
  libavdevice    61.  3.100 / 61.  3.100
  libavfilter    10.  4.100 / 10.  4.100
  libswscale      8.  3.100 /  8.  3.100
  libswresample   5.  3.100 /  5.  3.100
  libpostproc    58.  3.100 / 58.  3.100

with this PR, lmms --version will now look like this:

lmms --version

LMMS 1.3.0-alpha.1.793+pr7780.8f7b744
(OS X arm64, Qt 5.15.16, GCC Apple LLVM 15.0.0 (clang-1500.3.9.4))

Build options:
LMMS_HAVE_CALF='TRUE' LMMS_HAVE_CAPS='TRUE' LMMS_HAVE_CARLA='TRUE'
LMMS_HAVE_CMT='TRUE' LMMS_HAVE_CTYPE_H='1' LMMS_HAVE_FCNTL_H='1' LMMS_HAVE_FLUIDSYNTH='TRUE'
LMMS_HAVE_GIG='TRUE' LMMS_HAVE_JACK='TRUE' LMMS_HAVE_JACK_PRENAME='TRUE' LMMS_HAVE_LIBRT=''
LMMS_HAVE_LOCALE_H='1' LMMS_HAVE_LV2='TRUE' LMMS_HAVE_MP3LAME='TRUE' LMMS_HAVE_OGGVORBIS='TRUE'
LMMS_HAVE_PORTAUDIO='TRUE' LMMS_HAVE_PROCESS_H='' LMMS_HAVE_PTHREAD_H='1' LMMS_HAVE_SCHED_H='1'
LMMS_HAVE_SDL='TRUE' LMMS_HAVE_SEMAPHORE_H='1' LMMS_HAVE_SF_COMPLEVEL='' LMMS_HAVE_SID='TRUE'
LMMS_HAVE_SNDFILE_MP3='TRUE' LMMS_HAVE_SOUNDCARD_H='' LMMS_HAVE_STK='TRUE' LMMS_HAVE_STRING_H='1'
LMMS_HAVE_SWH='TRUE' LMMS_HAVE_SYS_IOCTL_H='1' LMMS_HAVE_SYS_IPC_H='1' LMMS_HAVE_SYS_PRCTL_H=''
LMMS_HAVE_SYS_SOUNDCARD_H='' LMMS_HAVE_SYS_TIMES_H='1' LMMS_HAVE_SYS_TIME_H='1' LMMS_HAVE_SYS_TYPES_H='1'
LMMS_HAVE_TAP='TRUE' LMMS_HAVE_UNISTD_H='1' LMMS_HAVE_WEAKJACK='TRUE' WANT_ALSA='OFF'
WANT_ALSA='OFF' WANT_CALF='ON' WANT_CAPS='ON' WANT_CARLA='ON' WANT_CMT='ON'
WANT_CPACK_TARBALL='OFF' WANT_DEBUG_ASAN='OFF' WANT_DEBUG_CPACK='OFF' WANT_DEBUG_FPE='OFF'
WANT_DEBUG_GPROF='OFF' WANT_DEBUG_GPROF='OFF' WANT_DEBUG_MSAN='OFF' WANT_DEBUG_TSAN='OFF'
WANT_DEBUG_UBSAN='OFF' WANT_GIG='ON' WANT_JACK='ON' WANT_LV2='ON' WANT_MP3LAME='ON'
WANT_OGGVORBIS='ON' WANT_OSS='OFF' WANT_OSS='OFF' WANT_PORTAUDIO='ON' WANT_PULSEAUDIO='OFF'
WANT_PULSEAUDIO='OFF' WANT_SDL='ON' WANT_SF2='ON' WANT_SID='ON' WANT_SNDIO='ON' WANT_SOUNDIO='OFF'
WANT_SOUNDIO='OFF' WANT_STK='ON' WANT_SUIL='ON' WANT_SWH='ON' WANT_TAP='ON' WANT_VST='OFF'
WANT_VST='OFF' WANT_VST_32='ON' WANT_VST_64='ON' WANT_WEAKJACK='ON' WANT_WINMM='OFF' 


Copyright (c) 2008-2025 LMMS Developers

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.

Try "/Users/owner/Downloads/LMMS.app/Contents/MacOS/lmms --help" for more information.

I think it's a neat feature but it also puts a pretty large wall of text into our version information. I'd like a few developer OK's before merging.