Add support for twitter legacy oauth 1.0A in v5

[svarup]

Goals

As in Twitter OAuth 2.0, there is no way to get the user's email address. Twitter does not provide any Scope to get an authenticated user's email address. Even if you check "Request email from users" in the Twitter App you won't get the email address. But if you use OAuth 1.0A you can request email using "include_email=true" scope.

Non-Goals

No response

Background

Currently, in v5 there is only an OAuth 2.0 way in Twitter but we can't get email address. Please add OAuth 1.0A support that we have in v4

Proposal

Please add legacy Twitter OAuth 1.0A provider in V5

[matt-roz]

I had to painfully come to the conclusion that requiring email for them user locks one into Twitter OAuth 1.0A, which is no longer supported by v5.

This unfortunately means v4 users that employ this restriction (requiring email) cannot migrate to v5.