Add forRootAsync for configuration via configService about azure-storage

[DimosthenisK]

Hey, just for a notice, I went ahead and bypassed this.
I created a wrapper module, and I instanciate the DynamicModule from it.

import * as azure from '@nestjs/azure-storage';

export const AZURE_STORAGE_MODULE_OPTIONS = azure.AZURE_STORAGE_MODULE_OPTIONS;

@Module({
    providers: [
        azure.AzureMulterStorageService,
        azure.AzureStorageService,
    ],
    exports: [
        azure.AzureMulterStorageService,
        azure.AzureStorageService,
        azure.AZURE_STORAGE_MODULE_OPTIONS,
    ],
})
export class AzureModule {
    static withConfig(
        optionsProvider: Provider<azure.AzureStorageOptions>
    ): DynamicModule {
        return {
            module: AzureModule,
            providers: [optionsProvider],
        };
    }
}

[manekinekko]

Interesting. Thanks for sharing.

[ksivamuthu]

@manekinekko I've added PR to this issue. Please review and let me know your suggestions.