Fix various /*.get endpoints returning error 500 when not provided with id

[unnawut]

Issue/Task Number: #755
Closes #755

Overview

This PR adds input handling for when id is not provided to various /*.get endpoints.

⚠️ This PR add/edit the controller tests. This will require migrating these tests manually to the unified controller tests on master branch.

Changes

• Add a handle_error(conn, :missing_id) or handle_error(conn, :invalid_parameter, _) to missing controller fallbacks.

Implementation Details

Some older code seems to be missing a fallback for when id is not provided.

Note that there are still some inconsistency in how error messages are returned. Some endpoints would return simply "Invalid parameter provided.", while some others would return "Invalid parameter provided. `id` is required."

But these inconsistencies are a cosmetic issue, since providers should not be parsing the plaintext description and there are a lot of places that can be improved. Will open a separate ticket for this.

Usage

Try, for example, /account.get_wallets without providing an id. It should return a proper error response. E.g.

curl 'http://localhost:4000/api/admin/account.get_wallets' \
-H 'Authorization: OMGAdmin <truncated>' \
-H 'Content-Type: application/json;charset=UTF-8' \
-H 'Accept: application/vnd.omisego.v1+json' \
-d '{"per_page":10,"sort_by":"identifier","sort_dir":"desc","owned":true}'

Impact

No changes to the API specs or DB schema.