Try enforcing contextual type of array literal elements

Part of #19236

Code

const s1: string[] = ["x", 3, null as any];
const s2: string[] = ["x", 3];

Expected behavior:

• s1 should be an error
• s2 should have an error span on 3

Actual behavior:

• s1 is not an error
• s2 has an error span on s2, which makes it impossible to figure out which element is wrong

Hypothesis: When checking a contextually-typed array literal, if an element type isn't assignable to the contextual type, issue an error on that element and return unknownType

Reproduce los dos ejemplos de literales de array del issue e inspecciona la comprobación contextual que realiza el compilador de los elementos de los literales de array. Se considera terminado cuando se rechaza la primera asignación y la segunda informa del error en el elemento no válido 3 en lugar de hacerlo en s2.