[Bug]: Env var handling

[eaglesemanation]

Binner version

v2.6.18

Operating System

Docker

Describe the bug and the steps to reproduce it

1. According to both https://hub.docker.com/r/binnerofficial/binner and https://github.com/replaysMike/Binner/wiki/Docker I'm supposed to set BINNER_PROVIDER to change db.
   But according to

   Binner/Binner/Library/Binner.Model/Configuration/EnvironmentVarConstants.cs

   Line 20 in e6a0f4f

   public const string StorageProviderName = "BINNER_DB_PROVIDER"; // Name of the storage provider

   it's supposed to be BINNER_DB_PROVIDER

2. This one I'm not that certain in, because I'm struggling to read C#. This seems to access a dictionary by plain keys like Host:
   

   Binner/Binner/Binner.Web/Database/ConnectionStringConstructor.cs

   Lines 18 to 21 in e6a0f4f

   	var host = configuration.ProviderConfiguration
   	.Where(x => x.Key == "Host")
   	.Select(x => x.Value)
   	.FirstOrDefault();

   
   While this sets dictionary by using env var names, like BINNER_DB_HOST:
   

   Binner/Binner/Library/Binner.Model/Configuration/EnvironmentVarConstants.cs

   Lines 55 to 57 in e6a0f4f

   	var dbHost = System.Environment.GetEnvironmentVariable(EnvironmentVarConstants.StorageProviderHost);
   	if (!string.IsNullOrEmpty(dbHost))
   	storageProviderConfig.ProviderConfiguration[EnvironmentVarConstants.StorageProviderHost] = dbHost;

   
   So if I'm correct those env vars are never actually read. Currently I'm getting an error saying Host can't be null, even though env shows otherwise:

> echo $BINNER_DB_HOST
binner-pg-rw

(Don't worry about host name being weird, k8s DNS handles that fine)

Would you like to attach your appsetings.json configuration?

No response

Screenshots or Videos (Optional, but they help!)

No response

Are you able to contribute a PR? (No is ok!)

None