Database creation option and choice of utf8/utf8mb4 for tables
Missing exception:title key; Fixed schema issue with full text key; Improved user creation logic
Merge commit 'c2047e43868c6e9fd95fc3b16be99f3ff4bf70a4' from upstream into database-install
feature(install): version_compare, early-return style, introductory text for step 3

Function checkDatabaseSettings now uses version_compare for MySQL version check
Function checkDatabaseSettings now adopts early-return style
In install/en.php file, improved introductory text for install step 3 (database)

As per comments to PR #6527
Merge branch 'database-install' into 1.x

Conflicts:
	engine/classes/ElggInstaller.php
chore(git): new branch for database install enhancements (old PR #6527)

Changes brought into this new branch
- database creation option and choice of utf8/utf8mb4 for tables
- missing exception:title key; fixed schema issue with full text key; improved user creation logic
- function checkDatabaseSettings now uses version_compare for MySQL version check
- function checkDatabaseSettings now adopts early-return style
- in install/en.php file, improved introductory text for install step 3 (database)

New PR needed as cannot bring old commit comments inline with new requirements