fix(mtr):move character_set to test.character_set, fix main mtr_test and innodb mtr_test(#277) (#335)

* fix(mtr):fix innodb mtr and mv some test to test/innodb

* fix(mtr):move character_set to test/main/

fix(mtr):mv main mtr character_set test to test/main/cahracter_set

fix(mtr):mv myisam error mtr-test to test/main/myisam

fix(mtr):add optimizer_switch to include/default_mysqld.cnf

* fix(mtr):fix main mtr optimizer_switch amd mv some test to test/main
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