Add a linter rule for self member references

Summary:
Ref T7409. Adds a linter rule for the following:

• self:: is used instead of Self::.
• self:: is used for local static member reference.
• self:: is used instead of self ::.

Based on Squiz_Sniffs_Classes_SelfMemberReferenceSniff.

Test Plan: Added unit tests.

Reviewers: epriestley, Blessed Reviewers

Reviewed By: epriestley, Blessed Reviewers

Subscribers: Korvin, epriestley

Maniphest Tasks: T7409

Differential Revision: https://secure.phabricator.com/D12370