Add error codes and error messages to failed results (#89)

# Description

- Added an Error Code (enum) and Error Message (string) to all the failed results

#53

## Type of change

Please delete options that are not relevant.

- [x] New feature (non-breaking change which adds functionality)

# How Has This Been Tested?

- This has been tested both manually as well as the unit tests

# Checklist

- [ ] My code follows the style guidelines of this project
- [ ] I have performed a self-review of my own code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [ ] My changes generate no new warnings
- [ ] I have added tests that provde my fix is effective or that my feature works
- [ ] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged and published in downstream modules

Reviewed-on: https://gitea.vylpes.xyz/RabbitLabs/random-bunny/pulls/89
Co-authored-by: Ethan Lane <ethan@vylpes.com>
Co-committed-by: Ethan Lane <ethan@vylpes.com>

src/constants/ErrorCode.ts

@@ -0,0 +1,6 @@
+export enum ErrorCode {
+    Unknown,
+    FailedToFetchReddit,
+    UnableToParseJSON,
+    NoImageResultsFound,
+}

src/constants/ErrorMessages.ts

@@ -0,0 +1,5 @@
+export default class ErrorMessages {
+    public static readonly FailedToFetchReddit = "Failed to fetch result from Reddit";
+    public static readonly UnableToParseJSON = "Unable to parse the JSON result";
+    public static readonly NoImageResultsFound = "No image results found in response from Reddit";
+}