Feature request - default timeout as provider config

[pregress]

Change the defaultTimeout to be variable that can be set in the provider: https://github.com/betr-io/terraform-provider-mssql/blob/b5224f97c0ef4c6bf4a437b0ca2a852faa7e08fc/mssql/provider.go#L27

Why? If you use azuread_default_chain_auth sometimes you receive a timeout if you depend on Azure CLI credential.

Example usage:

provider "mssql" {
  debug = "false"
  defaultTimeout = 60
}