Surface location in parse errors

[scsmithr]

Surfaces location in ParserError to allow library users to be able to enrich error messages that are shown to end users. The annotate_with_error shows an example use case where we can generate an error string that shows the full query with the error displayed inline.

For example, if I submit the following query:

select
    a,
    b,,
from public.letters
order by b

I can take the error from parsing that, and use the extra location info to be able to generate the following:

select
    a,
    b,,
      ^ Expected an expression:, found: ,
from public.letters
order by b

---

This is a breaking change as it's touching ParserError, and downstream projects (datafusion) would be impacted by this (the custom sql parser in particular). I added in ParserError::new_parser_error to make the changes need relatively straightforward.

Longer term, I think ParserError can be improved a bit more to allow even better diagnostics to be displayed to the end user. What I'm thinking:

pub struct ParserError<'a> {
    /// The kind of the error, parsing, tokenenizing, recursion limit, etc.
    pub kind: ParserErrorKind,

    /// Error message to show the user.
    pub msg: String,

    /// The query currently being parsed.
    pub query: &'a str,

    /// Location context (or a span if that gets threaded around).
    pub location: Option<Location>,
}

Obviously that's an even more breaking change, but I think it'd be worth it to make the errors returned to users very informative.