chore: Move bundling from CMake to Python (#508)

Some of the work with the Meson build system has highlighted that the
bundling is currently very inflexible because it's implemented in CMake.
This was initially done because it made it easy to use
`configure_file()` in CMake to keep the version information consistent,
and because it allowed a straightforward path to testing the bundled
files in the same way as the normal build.

This had the unfortunate side effect of requiring CMake to "build" the R
or Python packages as is generally confusing, and used the CMake
"install" in a confusing way (it installed sources). Instead, we can do
this with a Python script (and call that from CMake, R, and Python). The
testing of the namespaced builds is still done in CMake, which is
essential to ensure that both build types are tested in the same way.

This also closes #485 by prefixing all nanoarrow includes with
"nanoarrow/" in the source files. Many of them had to not use this
prefix because when the files were bundled they weren't always bundled
into a "nanoarrow/" directory. This feature has been moved to the
bundling script which can now namespace or un-namespace the nanoarrow
includes.

.github/workflows/bundle.yaml

@@ -35,28 +35,15 @@ jobs:
 
       - name: Bundle nanoarrow
         run: |
-          mkdir build && cd build
-          cmake .. -DNANOARROW_BUNDLE=ON
-          cmake --build .
-          cmake --install . --prefix=../nanoarrow-latest
-          cd ..
-          cp LICENSE.txt nanoarrow-latest/LICENSE.txt
-
-      - name: Bundle nanoarrow_ipc
-        run: |
-          rm -rf build
-          mkdir build && cd build
-          cmake .. -DNANOARROW_BUNDLE=ON -DNANOARROW_IPC=ON
-          cmake --build .
-          cmake --install . --prefix=../nanoarrow-latest
+          python3 ci/scripts/bundle.py \
+            --source-output-dir=nanoarrow-latest \
+            --include-output-dir=nanoarrow-latest \
+            --header-namespace= \
+            --with-device \
+            --with-ipc \
+            --with-flatcc
 
-      - name: Bundle nanoarrow_device
-        run: |
-          rm -rf build
-          mkdir build && cd build
-          cmake .. -DNANOARROW_BUNDLE=ON -DNANOARROW_DEVICE=ON
-          cmake --build .
-          cmake --install . --prefix=../nanoarrow-latest
+          cp LICENSE.txt nanoarrow-latest/LICENSE.txt
 
       - name: Compress bundle
         run: |

.github/workflows/examples.yaml

@@ -60,13 +60,9 @@ jobs:
       - name: Minimal Vendored Example
         run: |
           cd examples/vendored-minimal
-          mkdir build && cd build
-          cmake ../../.. -DNANOARROW_BUNDLE=ON -DNANOARROW_NAMESPACE=ExampleVendored
-          cmake --build .
-          cmake --install . --prefix=../src
-
-          cd ../src
+          python3 ../../ci/scripts/bundle.py --source-output-dir=src --include-output-dir=src
 
+          cd src
           gcc -c library.c nanoarrow.c
           ar rcs libexample_vendored_minimal_library.a library.o nanoarrow.o
           gcc -o example_vendored_minimal_app app.c libexample_vendored_minimal_library.a
@@ -85,18 +81,15 @@ jobs:
       - name: Ipc Vendored Example
         run: |
           cd examples/vendored-ipc
-          mkdir build && cd build
-          cmake ../../.. -DNANOARROW_BUNDLE=ON -DNANOARROW_NAMESPACE=ExampleVendored
-          cmake --build .
-          cmake --install . --prefix=../src/nanoarrow
-          mkdir ../build_ipc && cd ../build_ipc
-          cmake ../../.. -DNANOARROW_BUNDLE=ON -DNANOARROW_IPC=ON
-          cmake --build .
-          cmake --install . --prefix=../src/nanoarrow
-
-          cd ../src
-
-          gcc -c library.c nanoarrow/nanoarrow.c nanoarrow/flatcc.c nanoarrow/nanoarrow_ipc.c -I./nanoarrow -I./nanoarrow/flatcc
+          python3 ../../ci/scripts/bundle.py \
+            --source-output-dir=src \
+            --include-output-dir=src \
+            --symbol-namespace=MyProject \
+            --with-ipc \
+            --with-flatcc
+
+          cd src
+          gcc -c library.c nanoarrow.c flatcc.c nanoarrow_ipc.c -I.
           ar rcs libexample_vendored_ipc_library.a library.o nanoarrow.o nanoarrow_ipc.o flatcc.o
           gcc -o example_vendored_ipc_app app.c libexample_vendored_ipc_library.a