Replace all title= attributes with aria-label= (D8)

Problem/Motivation

Per #3158395: Avoid similar-sounding links with different purposes (D8) it is recommended to change the "title" attribute on links to "aria-label".

Proposed resolution

Change all "title" attributes to "aria-label".

Remaining tasks

Make the changes.

User interface changes

All "title" attributes will change to "aria-label".

API changes

n/a

Data model changes

n/a