Should application be detected from header or IfcApplication, and what's the correct header syntax for MVD?

[Moult]

See IfcOpenShell/IfcOpenShell#2526

[aothms]

According to the docs referenced by @Moult in the issue above there are a couple issues with:

https://github.com/buildingSMART/validate/blob/release/application/checks/info.py#L22

• We should use the grammar on p4 not just arbitrarily split on whitespace
• Should not only read description[0] but all of description

And in general

• We should report on invalid ifc-header syntax
• We should check header attribute value types in general in validate.py
• We should check some of the header values for correctness such as implementation level and the time stamp

Thanks @Moult

CC @evandroAlfieri