Query parser error propagation

[OmarTawfik]

The following query is incorrect, as the variant: filter should be applied to each literal in the choices:

Query::parse(
    "[PathImport
        path: [StringLiteral
            @variant variant: ([DoubleQuotedStringLiteral] | [SingleQuotedStringLiteral])
        ]
    ]",
)

It would produce this error:

"Parse error:
expected ']' at: path: [StringLiteral
            @variant variant: ([DoubleQuotedStringLiteral] | [SingleQuotedStringLiteral])
                ]
            ]
Alt at: [PathImport
                path: [StringLiteral
            @variant variant: ([DoubleQuotedStringLiteral] | [SingleQuotedStringLiteral])
                ]
            ]
"

The correct version would be:

Query::parse(
    "[PathImport
        path: [StringLiteral
            @variant (variant: [DoubleQuotedStringLiteral] | variant: [SingleQuotedStringLiteral])
        ]
    ]",
)

However, the error position is inaccurate, as it points to the parent PathImport node, rather than being narrowed down to the specific ( ) node that has the error. We should look into the nom error propagation in crates/metaslang/cst/src/query/parser.rs, and see if we can control/improve.