Feature request: Auto-convert .format() to f-string

[WSLUser]

Environment data

• VS Code version: 1.35 (Insiders)
• Extension version (available under the Extensions sidebar): Version: 2019.4.12954
  Publisher: Microsoft
• OS and version: N/A
• Python version (& distribution if applicable, e.g. Anaconda): 3.7.3
• Type of virtual environment used (N/A | venv | virtualenv | conda | ...): N/A
• Relevant/affected Python packages and their versions: 3.6+

Expected behaviour

I highlight a print statement that uses .format and get an option to convert to f-string using the UI menu or through a shortcut.

Actual behaviour

Per this blog Pycharm supports f-strings. From the blog: "Python programs that still use the .format() method, you can just press Alt+Enter and select that intention to convert everything to the new syntax."

I want to see the same feature in VSCode with possibly a different shortcut.

Steps to reproduce:

1. Highlight a print statement with a .format() in it. See only the usual options available from the menu e.g. "Format Document", etc.

[WSLUser]

In case this helps, there is a solution for simple statements in https://github.com/asottile/pyupgrade but as it states:

note: pyupgrade is intentionally timid and will not create an f-string if it would make the expression longer or if the substitution parameters are anything but simple names or dotted names (as this can decrease readability).

When using pyupgrade, it failed to convert due to it's intentional timidness. Using Pycharm, I was successful. Readability was still there in my case. In fact, it actually decreased some confusion as unicode handling such as using '/n' were involved.