Migrate appveyor build to MySql 8

[fredericDelaporte]

This is an attempt to fix the appveyor build. MySql 5.7 seems to have disappeared from the appveyor images without notice. We would have to use MySql 8 instead.

See appveyor/ci#3895.

[fredericDelaporte]

According to this SO answer, it seems we must use at least MySql.Data 8.0.30 for recent MySql servers. We are using the 8.0.27 one.

[fredericDelaporte]

All MySql builds fail now, downgrading from 8.2.0 to 8.0.33. There is some issues with lock tests and 8.2.0.

[hazzik]

@fredericDelaporte .33 will fail as well.

In #3095 (comment):

@bahusoid: Looks like v8.0.30 is the latest working version.

[hazzik]

@fredericDelaporte, this is the issue: #1302

[hazzik]

I would suggest to quote groups table in this test case for the purpose of this ticket, and drop the keywords from here.

[bahusoid]

@fredericDelaporte, this is the issue: #1302

Doesn't look like it to me. #1302 is about using Configuration.GenerateSchemaCreationScript directly (not via SchemaExport) in user code. But quoting is not executed there, instead SchemaExport.Create should be used (that's the only place when auto-quote setting is applied). Am I missing something?

Also if I understand correctly some new words are now reserved in MySql 8 (like groups) and we don't do auto-quoting by default in tests. So failed tests are expected to me - we need to quote new reserved words or register new words + enable auto-qouting in affected test cases.

[fredericDelaporte]

So, I could either enable auto-quoting on that test, or drop the change and directly quote that new reserved word.

[fredericDelaporte]

Replaced by #3453