Make extension lazy loading optional

[Rafq77]

Issue Description

The extension is lazily loaded. That is, looking at package.json:

...
    "activationEvents": [
        "onDebugInitialConfigurations",
        "onLanguage:python",
        "onDebugResolve:python",
        "workspaceContains:mspythonconfig.json",
        "workspaceContains:pyproject.toml",
        "workspaceContains:Pipfile",
        "workspaceContains:setup.py",
        "workspaceContains:requirements.txt",
        "workspaceContains:manage.py",
        "workspaceContains:app.py"
    ],
...

The Python extension is activated when a file which language type is set to Python is currently active or specific files such as: requirements.txt are present in the workspace.

Suggested feature

I'd like to be able to have the extension loaded upon vscode startup onStartupFinished, regardless if the necessary files are present or a python file is active.

In order to not deteriorate loading times for big python projects, I would like to have this feature to be optional, so it could be toggled in the extension settings (disabled by default).

Rationale

We use Python as a helper in our C++ project. We would like the test explorer to discover tests upon vscode startup, which in turn requires the extension to be active. While reopening the project, recent python files remain open in background tabs, switching tabs just to trigger the loading of the extension feels tedious.

[karthiknadig]

You may have to use extensions like: https://marketplace.visualstudio.com/items?itemName=mjcrouch.activator to force python extension to activate for you. Unfortunately, there is no way to have both the filter (as you pointed out above) and have it activate always.