type safety for provided?

[philipbjorge]

When referencing a singleton via foo.provided.bar, we lose type safety because provided always resolves to the ProvidedInstance rather than the specific type of the dependency.

    settings = providers.Singleton(Settings)
    
    identity_container = providers.Container(
        IdentityContainer,
        base_url=settings.provided.IDENTITY_SERVICE_BASE_URL,
    )

Expected
settings.provided resolves to Settings

Actual
settings.provided resolves to ProvidedInstance

This seems like an easy change to make -- Is there any reason this wouldn't work if I opened a PR?

[toinbis]

@philipbjorge - installed your fix from git, works like magic! @rmk135 is there any chance we could get it merge?

[philipbjorge]

@toinbis -- Another type update :)
#744

[ZipFile]

Done in #733 and #744.