Implement type safe error handling

[7tint]

Ticket link

Closes #99

Implementation description

• Added a getErrorMessage utility function
• Replace all errors with type unknown
• Replaced current Logger messages to use getErrorMessage

Steps to test

1. Make sure that application runs as expected and errors are being logged properly

What should reviewers focus on?

• Didn't miss any errors to be replaced

Checklist

• My PR name is descriptive and in imperative tense
• My commit messages are descriptive and in imperative tense. My commits are atomic and trivial commits are squashed or fixup'd into non-trivial commits
• I have run the appropriate linter(s)
• I have requested a review from the PL, as well as other devs who have background knowledge on this PR or who will be building on top of this PR

[sherryhli]

There are some cases where the error is being explicitly typed as any, do you mind addressing those too? They're flagged by the linter github actions workflow.

The rest looks good!

[7tint]

There are some cases where the error is being explicitly typed as any, do you mind addressing those too? They're flagged by the linter github actions workflow.

The rest looks good!

Just fixed this up. 🔨

Should we do anything about the firebaseError and postgresError error types? They are currently marked as type any.

[sherryhli]

Should we do anything about the firebaseError and postgresError error types? They are currently marked as type any.

@lambo-liu Yes, let's type them as unknown as well

[7tint]

Should we do anything about the firebaseError and postgresError error types? They are currently marked as type any.

@lambo-liu Yes, let's type them as unknown as well

@sherryhli Should be good now! Let me know if there is anything else we need to patch up 🪡

[sherryhli]