[ENH] Start the networks module with EEGNet example

[hadifawaz1999]

Part of #119

This PR implements:

• networks module with base
• testing base
• adds [dl] in pyproject for deep learnins deps
• implements EEGNet network in the networks module
• in order to make sure if the re-implementation is correct, the test makes sure our implementation produces the same output shape that is expected by EEGNet *theoretical caclulation of how each layer handles the input shape