Parse true and false as identifiers in mssql

[lovasoa]

fixes #1508

[lovasoa]

There are 7 failing tests at the moment. From a quick glance, it looks like it's the tests that are incorrect: they rely on the existence of boolean literals in all dialects.

[lovasoa]

Ok, I fixed all the tests, this is ready for review @iffyio, @alamb :)

[iffyio]

LGTM! cc @alamb

[alamb]

Ci appears to be failing on this PR

[lovasoa]

@alamb : Sorry ! It's fixed now.

[alamb]

🤔 I don't know why but this repo now seems to require manually starting CI. I will look into it

[git-hulk]

@alamb It's the Apache organization's setting behavior if my memory serves. All repositories in the organization are required to manually trigger CI for non-members.

[alamb]

I have filed https://issues.apache.org/jira/browse/INFRA-26268 for trying to ensure CI runs automatically

[alamb]

@alamb It's the Apache organization's setting behavior if my memory serves. All repositories in the organization are required to manually trigger CI for non-members.

Thanks @git-hulk -- arrow and DataFusion both are set to run CI after the first time a contributor has had a PR merged. I filed https://issues.apache.org/jira/browse/INFRA-26268 to request the same setting on this repository (what it used to be as well)