Consolidate mm-redux/store into app/store

Description

As part of the consolidation process:

  1. Remove unnecessary code (ie, code that doesn’t apply to the mobile app)

  2. Optimize wherever possible for better performance on the mobile app

QA Test Steps

see desc on PR

Mana

None

Assignee

Elias Nahum

QA Assignee

Saturnino Abril

Reporter

Miguel Alatzar

Fix versions

Mattermost Team

Mobile

Sprint

None

Labels

QA Testing Areas

Mobile - RN

GitHub Issue

None

Components

None
Configure