Improve error message for CREATE EXTERNAL TABLE typos

[alamb]

If a user puts a typo like this (HEAD rather than HEADER) in their SQL

CREATE EXTERNAL TABLE t(c1 int)
STORED AS CSV
WITH HEAD ROW
LOCATION 'foo.csv';

The Parser returns the somewhat confusing error sql parser error: Missing LOCATION clause in CREATE EXTERNAL TABLE statement

It would be great if the message was something more "expected LOCATION, HEADER, ... got HEAD" that gave the user a hint of what was was wrong

See original suggestion posted by @tz70s in #6257 (comment)

[parkma99]

I'm going to work it