Defer import of aio_pika

[unkcpz]

Replace #287

(I'll do a benchmark on import aiida.orm with this)

[unkcpz]

I didn't detect any import performance improvement, maybe I did something wrong? @danielhollas

I run:

hyperfine -w 5 'python -c "import aiida.orm"'

[sphuber]

I didn't detect any import performance improvement, maybe I did something wrong? @danielhollas

I run:

hyperfine -w 5 'python -c "import aiida.orm"'

Well, you now add the imports to plumpy.exceptions and that is star-imported in plumpy/__init__.py so you are undoing moving the import in plumpy.processes are you not?

[unkcpz]

plumpy.exceptions and that is star-imported in plumpy/init.py

Right, that's true. But it is not easy to seperate the aiopika exception from the regular exceptions. I create and rmq module for that but it seems a bit overkill.
I am working on adding support for not using rabbitmq, and in the end I think it should have plumpy to support both. A good start would to have a module for things that related to rabbitmq related libraries (aio_pika, kiwipy..).

[unkcpz]

I'll include this in #297, since this is not urgent fix.