[Setup] Add support for editable mode

Context

Add support for editable/development mode build.

Basically reported necessary changes for supporting build in development mode with:

Refer to same changes done in aidge_core merge request aidge_core!154 (merged)

Modified files

Modified:

• setup.py: account for editable mode and pass python module installation directory to cmake, remove useless copy of module now directly installed by cmake
• cmake: add installation of python module
• README.md: add short description and refer to aidge_core README for details

Detailed major modifications

No incompatible modification. Add new support for development mode.

TODO

Nope

README.md

@@ -23,9 +23,23 @@ Those operators can be used on any machine with an Linux OS.
 pip install . -v
 ```
 > **TIPS :** Use environment variables to change compilation options :
-> - `AIDGE_INSTALL` : to set the installation folder. Defaults to /usr/local/lib. :warning: This path must be identical to aidge_core install path.
-> - `AIDGE_PYTHON_BUILD_TYPE` : to set the compilation mode to **Debug** or **Release** 
-> - `AIDGE_BUILD_GEN` : to set the build backend with 
+> - `AIDGE_INSTALL` : to set the installation folder. Defaults to `<python_prefix>/lib/libAidge`. :warning: This path must be identical to aidge_core install path.
+> - `AIDGE_PYTHON_BUILD_TYPE` : to set the compilation mode to **Debug** or **Release** or "" (for default flags). Defaults to **Release**.
+> - `AIDGE_BUILD_GEN` : to set the build backend (for development mode) or "" for the cmake default. Default to "".
+
+## Pip installation for development
+
+To setup using pip in development (or editable mode), use the `--no-build-isolation -e` options to pip.
+
+For instance run the following command in your python environnement for a typical setup :
+``` bash
+export AIDGE_PYTHON_BUILD_TYPE=         # default flags (no debug info but fastest build time)
+export AIDGE_PYTHON_BUILD_TYPE=Debug    # or if one really need to debug the C++ code
+pip install -U pip setuptools setuptools_scm[toml] cmake   # Pre-install build requirements (refer to the pyproject.toml [build-system] section)
+pip install -v --no-build-isolation -e .
+```
+
+Refer to `aidge_core/README.md` for more details on development build options.
 
 ### Standard C++ Compilation