Can we remove the dependency to Microsoft.Data.SqlClient in Arcus.Observability.Telemetry.Sql

[fgheysels]

The Arcus Observability.Telemetry.Sql project now has a dependency on the Microsoft.Data.SqlClient package.
We use this package now just so that we can use the SqlConnectionStringBuilder class. One of the LogSqlDependency methods takes a parameter that accepts a connection-string to a Sql database. We use the SqlConnectionStringBuilder to parse this connection-string and retrieve the servername and the database-name from the connection-string.

I think it is kind of bloated and unnecessary to have a dependency on this package just for this. Since a connection-string is nothing more then a string with multiple key/value pairs, I wonder if we cannot just write a simple 'parser' ourselves that retrieves the parts that we need.

I'm thinking of something really simple like this:

var connectionString = "Server=myServerAddress;Database=myDataBase;User Id=myUsername;Password=myPassword;";

var parts = connectionString.Split(';')
			.Select(part => part.Split('='))
			.Where(part => part.Length == 2)
			.Select(kv => new KeyValuePair<string,string>(kv[0],kv[1])).ToArray();

There are of course some edge cases, as a connection string can have a Server component, but it is also possible to have a Data Source component instead.

See also the comments in this PR: #485