meson: add necessary subprojects

Add subprojects for all the direct dependencies of the project such
that the project can be built outside of a Yocto SDK on a typical
Linux development system.

  - Update the .gitignore to ignore the subproject source directories.
  - Update the .gitignore to ignore alternative build subdirectory
    names as is typical with most projects in the openbmc organization.
  - Add wrap files for direct dependencies, copied from other
    repositories that already have the same dependencies.
  - Modify the meson.build dependency for libgpiod so that the C++
    bindings are included.
  - Add many missing dependencies throughout.
  - Sort all dependencies alphabetically for consistency.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I0feb6f0f175e6dba0b00a2c2b666eb0801575734
diff --git a/phosphor-power-sequencer/src/meson.build b/phosphor-power-sequencer/src/meson.build
index 590e10e..3d1c8d0 100644
--- a/phosphor-power-sequencer/src/meson.build
+++ b/phosphor-power-sequencer/src/meson.build
@@ -12,10 +12,11 @@
     'ucd90320_monitor.cpp',
     dependencies: [
         libgpiodcxx,
+        nlohmann_json_dep,
         phosphor_logging,
         sdbusplus,
         sdeventplus,
-        stdplus
+        stdplus,
     ],
     link_with: [
         libpower