[Feature] get_attention parameter in GlobalAttentionPooling

[decoherencer]

Description

@mufeili Added get_attention optional parameter to return node attention weights from GlobalAttentionPooling
from the https://discuss.dgl.ai/t/about-globalattentionpooling/2766

Checklist

• The PR title starts with [$CATEGORY] (such as [NN], [Model], [Doc], [Feature]])
• Changes are complete (i.e. I finished coding on this PR)
• All changes have test coverage
• Code is well-documented
• To the best of my knowledge, examples are either not affected by this change,
  or have been fixed to be compatible with this change

Changes

• optional parameter addition in forward

[dgl-bot]

To trigger regression tests:

• @dgl-bot run [instance-type] [which tests] [compare-with-branch];
  For example: @dgl-bot run g4dn.4xlarge all dmlc/master or @dgl-bot run c5.9xlarge kernel,api dmlc/master

[mufeili]

LGTM. Thanks!

[mufeili]

@decoherencer Could you fix these issues caught by CI?

python/dgl/nn/pytorch/glob.py:458:0: C0303: Trailing whitespace (trailing-whitespace)
python/dgl/nn/pytorch/glob.py:1268:0: C0304: Final newline missing (missing-final-newline)

You need to remove the extra empty spaces at the end of L458 and add a new empty line after L1268.

[decoherencer]

Sorry. I got into this weird state with my pip, which I only noticed now.
I tried with lint packages locally now. Thanks.
And instead of noticing the line number in CI issues for trailing whitespace, I removed the final newline in the last last last commit 😅

[mufeili]

Sorry. I got into this weird state with my pip, which I only noticed now. I tried with lint packages locally now. Thanks. And instead of noticing the line number in CI issues for trailing whitespace, I removed the final newline in the last commit 😅

@decoherencer No worries. There is something wrong with the CI. If you don't mind, I can directly modify your code when CI is back. Thanks.

[decoherencer]

If you don't mind, I can directly modify your code when CI is back. Thanks.

Sure. I pushed lint fix, it seems to have passed in last CI lint checks before it crashed on cpu build, you can modify if any other errors

[mufeili]

@decoherencer Thanks for your patience. The PR has been merged.

[decoherencer]

nice. Looking forward to help more

[mufeili]

Thanks. That will be great!