Make image for update-egis-db

[groutr]

The current LAMBDA uses AWS layers to manage dependencies. This PR switches to an image-based LAMBDA for better environment isolation/management.

ref: #1029

[shawncrawley]

Rather than update the terraform code for the update-egis-db function in-place in the Core/LAMBDA/viz_functions/main.tf file, I would like you to nest this as needed within the Core/LAMBDA/viz_functions/image_based/ folder, since we're converting it to an image-based Lambda (i.e. a Lambda based on a Docker image). I'll further ask that you follow the Terraform pattern that I used for `Core/LAMBDA/viz_functions/image_based/viz_schism_fim_processing, which was my first iteration and example of what I intend to eventually do for every Lambda as captured in issue #945. If you need some more context and guidance for this, please let me know.

[groutr]

@shawncrawley I think this is ready for review.