Pydev.Debugger extension

[omry]

Closes #214

See included doc for user facing description.

Example:
For this config:

simple = OmegaConf.create(
    {
        "a": "bar",
        "inter": "${a}",
        "inter2": "foo_${a}",
        "inter_error1": "${zzz}",
        "inter_error2": "foo_${zzz}",
        "missing": "???",
    },
)

Object inspection with USER flavor:

Object inspection with DEV flavor:

Object inspection with the resolver disabled (default behavior prior to extension):

[odelalleau]

I don't know much about Pydev.Debugger but overall looks good, just a few small comments

[omry]

@fabioz, thanks for the plugin API!
It would be awesome if you can take a quick look and provide feedback.

[odelalleau]

Looks good to VSCode debugger!