Fix unary operator precedence, allow some expressions as object values (#3053)

This commit improves the parser to fix some unintuitive results of the unary
operator `-` (e.g. `[-1 as $x | 1,$x]` is now `[1,-1]`, previously `[-1,-1]`).
Also, this commit now allows to use binary operator expressions, `reduce`,
`foreach`, `if`, and `try` expressions for object values.

Author: itchyny