change default table format to mysql_unicode

This is noted as a breaking change, though it will actually only affect
new installs.

Rationale: we are the fancy MySQL client.  Let's use the fancy format.
In 2026, terminals have Unicode support.

The test myclirc file remains set to "ascii" to avoid changing many
tests.

Preparation for release 2.0.

Author: rolandwalker

changelog.md

@@ -1,6 +1,11 @@
 Upcoming (TBD)
 ==============
 
+Breaking Changes
+---------
+* Change default table format to `mysql_unicode`.
+
+
 Internal
 ---------
 * Improve test coverage for DSN variable expansion.

mycli/myclirc

@@ -73,7 +73,7 @@ beep_after_seconds = 0
 # rst, simple, sql-insert, sql-update, sql-update-1, sql-update-2, textile,
 # tsv, tsv_noheader, vertical.
 # Recommended: mysql_unicode.
-table_format = ascii
+table_format = mysql_unicode
 
 # Redirected otuput format
 # Recommended: csv.