Intellisense tooltip applies text formatting on source code

Environment data

• VS Code version: 1.25.1
• Extension version (available under the Extensions sidebar): 2018.7.0
• OS and version: Windows 10
• Python version (& distribution if applicable, e.g. Anaconda): 3.7.0
• Type of virtual environment used (N/A | venv | virtualenv | conda | …): venv
• Relevant/affected Python packages and their versions: NA

Actual behavior

The tooltip applies text formatting to the displayed code, e.g. wrapping text in underscores italicizes it.

Expected behavior

The tooltip shows the code as it is written in the source.

Steps to reproduce:

1. Use the mypy linter
2. Define a variable in a class, using self, with underscores in its name
3. Assign a type to the variable with a type hint
4. Hover over it to see the Intellisense tooltip

Logs

Output for Python in the Output panel (View→Output, change the drop-down the upper-right of the Output panel to Python)

None

Output from Console under the Developer Tools panel (toggle Developer Tools on under Help)

None

[Spanfile]

@DonJayamanne A minimal sample:

class Test:
    def __init__(self):
        self._a_b: int = None

Python workspace settings:

{
    "python.pythonPath": "${workspaceFolder}\\venv\\Scripts\\python.exe",
    "python.linting.pylintEnabled": false,
    "python.linting.mypyEnabled": true,
    "python.jediEnabled": false
}

[luabud]

Fixed upstream (https://github.com/microsoft/python-language-server/issues/17)