chore(db): set collation specific to mariadb and fix phinx configuration

[tuxpiper]

This pull request makes the following changes:

• Sets the server collation in local environment to utf8_unicode_520_ci , which is based on UCA 5.2.0 weight keys (http://www.unicode.org/Public/UCA/5.2.0/allkeys.txt) (as opposed to UCA 4.0 in utf8_generic_ci). It should sort alphabets more reliably.
• Addresses a configuration flaw in phinx , which would ignore the character set configuration at the time of creating tables. So it seems that setting the collation is required.

Test checklist:

• run make start

• connect to the database and run SHOW TABLE STATUS where name like '%'; , the collation should be utf8mb4_unicode_520_ci .
  ( if you do this before applying the changes, you would see that the collation is utf8_* , or utf8mb3_* , which means we'd using a 3-byte charset that will not accept all the emojis 🤔😓🤮💣😵 and other higher-page characters )

• I certify that I ran my checklist

Fixes USH-1670

Ping @ushahidi/platform

[linear]

USH-1670 Local environment DB has wrong charset settings

[Mh-Asmi]

approved