Python development workload for Visual Studio 2019

### Overview

This package adds the Python development workload to an existing installation of Visual Studio 2019 (Enterprise, Professional or Community).

The lists of components included in this workload in respective Visual Studio 2019 products are shown here:

- [Enterprise](https://docs.microsoft.com/en-us/visualstudio/install/workload-component-id-vs-enterprise?view=vs-2019#python-development)

- [Professional](https://docs.microsoft.com/en-us/visualstudio/install/workload-component-id-vs-professional?view=vs-2019#python-development)

- [Community](https://docs.microsoft.com/en-us/visualstudio/install/workload-component-id-vs-community?view=vs-2019#python-development)

Visual Studio 2019 must be installed first, for example using Chocolatey packages: [visualstudio2019enterprise](https://chocolatey.org/packages/visualstudio2019enterprise), [visualstudio2019professional](https://chocolatey.org/packages/visualstudio2019professional), [visualstudio2019community](https://chocolatey.org/packages/visualstudio2019community).

### Customizations

The package passes all package parameters to the Visual Studio installer, enabling full customization of the installation. The possible parameters are [described here](https://docs.microsoft.com/en-us/visualstudio/install/use-command-line-parameters-to-install-visual-studio?view=vs-2019). The package passes `--norestart --includeRecommended` by default, and `--quiet`, unless `--passive` is specified in the package parameters.

By default, the package installs components required by and recommended for the workload. Package parameters can be used to adjust this behavior:

- `--no-includeRecommended` - Does not include the recommended components.

- `--includeOptional` - Includes the optional components.

By default, the package will detect installed Visual Studio products and add the workload to all products that support it and do not have it installed already.

In order to act on one specific product when several are installed, the product needs to be indicated to the package via parameters, either:

- `--installPath` - the path where the product is installed, for example "C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise"

or (both are needed):

- `--productId` - the identifier of the product, for example "Microsoft.VisualStudio.Product.Enterprise"

- `--channelId` - the release channel, should be "VisualStudio.16.Release"

Example 1. Installing the workload on all products, including recommended, but not optional components:

choco install visualstudio2019-workload-python