Support loading of Az module from any file path

## Description

Right now the Az module load is supported if it gets installed in $env:psmodulepath

if the Az modules are installed in $env:psmodulepath, the users can simply do Import-Module Az to load the all the Az modules, However the following is not possible to do the following

Save-Module -Name Az -Path C:\AzModules -Force
Import-Module c:\AzModules\Az

It is not possible to have AzureRM and Az side by side, having this support will really help customers move from AzureRM to Az while having the modules in the same machine

In AzureStack, many customers are just started to move from AzureRm to Az

## Steps to reproduce

```powershell

Save-Module -Name Az -Path C:\AzModules -Force
Import-Module c:\AzModules\Az

```