gLaSDI init

[xiaolong7]

gLaSDI source code and examples

[chldkdtn]

@dylan-copeland @kevinhkhuynh @siuwuncheung @friesb, this pr now introduces 17,796 new lines. I think this is okay. What do you think?

The main files you would like to review are the following four files:

• gLaSDI/src/autoencoder.py
• gLaSDI/src/sindy_utils.py
• gLaSDI/src/error_utils.py: 353 lines
• gLaSDI/src/training.py: 592 lines

For other files, let's just run each example to see if it runs without any errors.

[xiaolong7]

I am simplifying and testing the example notebooks and will push them very soon.