Errors and Warnings from the DesignTimeHost shouldn't be strings

[Alxandr]

Currently, the design time host gives diagnostic messages as strings (that VS and other consumers then have to parse). These strings obviously are generated from an object containing sources-file, line-number etc. and transforming that into a string, just to have the receiver parse it again seems kind of impractical. Shouldn't rather a representation of the raw object containing all the metadata be transferred, and then if a consumer needs it as a string it can generate it itself?

[glennc]

We recommend parsing the string, and that's what VS uses. But if you want this behavior then we could look at a pull request. Are you still interested in the change?

[Alxandr]

Yes. I still want this change. Parsing the error string is not pretty. I can look at implementing this and pull requesting it in a few days when I have time.

[glennc]

@Alxandr leaving this in the backlog for when you get to it.

[troydai]

Addressed in ac2f433