1. When parsing a `ValidatedString` from JSON and it fails, include a message about the expected format of the string.
- Reworked the classes using C#11 features to reduce the amount of boilerplate needed to add a new validated string type.
2. Change to use [RFC7807](https://www.rfc-editor.org/rfc/rfc7807) format for HTTP error responses. At the moment we returned the `Error` type which was undocumented.
3. Update CLI to parse RFC7807 responses.
Old error looked like:
```console
$ onefuzz containers create AbCd
ERROR:cli:command failed: request did not succeed: HTTP 500 -
```
New error looks like:
```console
$ onefuzz containers create AbCd
ERROR:cli:command failed: request did not succeed (400: INVALID_REQUEST): Unable
to parse 'AbCd' as a Container: Container name must be 3-63 lowercase letters, numbers,
or non-consecutive hyphens (see: https://docs.microsoft.com/en-us/azure/azure-resource-manager/management/resource-name-rules#microsoftstorage)
```
Closes#2661.
