Print offending object in runtime error messages

Print offending object in runtime error messages

When reporting an error to the user, add information about the offending
object/value (possibly truncated).

The goal is to give a user some context regarding which input object
caused the runtime error.

Examples:

    $ echo '"hello"' | ./jq '-.'
    jq: error: string ("hello") cannot be negated

    $ echo '"very-long-string"' | ./jq '-.'
    jq: error: string ("very-long-...) cannot be negated

    $ echo '["1",2]' | ./jq '.|join(",")'
    jq: error: string (",") and number (2) cannot be added

    $ echo '["1","2",{"a":{"b":{"c":33}}}]' | ./jq '.|join(",")'
    jq: error: string (",") and object ({"a":{"b":{...) cannot be added

    $ echo '{"a":{"b":{"c":33}}}' | ./jq '.a | @tsv'
    jq: error: object ({"b":{"c":33}}) cannot be tsv-formatted, only array

(Fix #754)