Feature request: Make all elements optionals in Lambda Handler type

[flochaz]

Description

Feedbacks from earlier adopters complained about handler type tight to decorators which make context and callback compulsory.

This was already identified in discussions #280

[github-actions]

⚠️ COMMENT VISIBILITY WARNING ⚠️

Comments on closed issues are hard for our team to see.
If you need more assistance, please either tag a team member or open a new issue that references this one.
If you wish to keep having a conversation with other community members under this issue feel free to do so.