Rename .theme files to .theme.inc

Problem/Motivation

The .theme files in the includes folder do not pass phpcs validation when being checked

Steps to reproduce

Using the AcquiaDrupalStrict rules with phpcs throws an error

Proposed resolution

Rename the .theme files to .theme.inc and update file pattern string in kinetic.theme

Remaining tasks

Implement changes

User interface changes

none

API changes

none

Data model changes

none