fix: Type override for BreadcrumbsRouter

[xueyawei]

Issue: type override cannot use union type, it will not work.

Solution: using Omit to delete original children first then do union type.

[xueyawei]

interface A {
a: string,
b: string,
}

type B = A & {
a: number
}

property 'a' in type B will be 'never' type.