Convert configs to classes instead of interfaces

[strawburster]

References

Add references/links to any related issues or PRs. These may include:

• Fixes Limit configuration available publicly in config.json #5030
• Related to Remove SSR related configuration from client app #5107

Description

Refactor app configuration to use class instances instead of interfaces. The benefit is that decorators can be used to specify metadata about config properties.

The decorators supplied in this PR for config properties are @Config.publish() @Config.env(name: string, loader?: (val: string) => any) and @Config.arrayOf(configClass)

• publish

This will mark a config property as 'public', which is used in the 'toPublic' method to filter only properties which should be available publicly.

• env

This will mark a config property as being able to be overridden by an environment variable with a specific name, and optionally a loader function which takes the string environment variable as its only parameter and returns the correct type for the property.

• arrayOf

This will mark a property as being an array of a specific type of config, so that when merging the config with a plain object, array properties are instantiated correctly.

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[github-actions]

Hi @strawburster,
Conflicts have been detected against the base branch.
Please resolve these conflicts as soon as you can. Thanks!

[strawburster]

The server failed to start, and I need the e2e results to move forward. Please re run this either once the server image is fixed or if you believe it was a fluke.

[github-actions]

Hi @strawburster,
Conflicts have been detected against the base branch.
Please resolve these conflicts as soon as you can. Thanks!

[strawburster]

Many more env and deepEnv decorators are needed in order to fully duplicate all currently available environment variables, I've only added the ones necessary to pass the tests so far. I would like some feedback on the approach. The core of it all is src/config/config.ts, which I feel is well documented. You can see it in use all throughout the folder. Most changes outside the src/config folder are just dropping the '-interface' in the filename for each config. The DefaultAppConfig, the config.server file, and the BuildConfig are all gone; instead AppConfig is the only type used throughout the project, and visibility is limited based on the decorators. The default values for config properties are defined, when possible, in the same file within the class definitions they are a part of. The comments within these need to be trimmed down because I copied a lot of duplicate things out of the DefaultAppConfig.