Spikemoid pr

[Michaeljurado42]

Issue Number: #230

Objective of pull request: Incorporate Spikemoid into lava-dl. Spikemoid is a spike based loss for probabilistic multi-label classification.

Pull request checklist

Your PR fulfills the following requirements:

• Issue created that explains the change and why it's needed
• Tests are part of the PR (for bug fixes / features)
• Docs reviewed and added / updated if needed (for bug fixes / features)
• PR conforms to Coding Conventions
• PR applys BSD 3-clause or LGPL2.1+ Licenses to all code files
• Lint (flakeheaven lint src/lava tests/) and (bandit -r src/lava/.) pass locally
• Build tests (pytest) passes locally

Pull request type

Please check your PR type:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation changes
• Other (please describe):

What is the current behavior?

• Lava-dl has no probabilistic multi-label classification losses. Spike Rate Loss may be used for multi-label classification but the mapping of spike rates to probabilities is unclear.

What is the new behavior?

• We introduce a spike based loss for multi-label classification into lava-dl. We also create a unit test file.

Does this introduce a breaking change?

• Yes
• No

Supplemental information

This PR stems from a discussion.

Thank you @audreydunn for your contributions!

[bamsumit]

Thanks @Michaeljurado42 for the contribution.