Add two confirmation modals in import

[etiennejouan]

https://www.figma.com/design/xt8O9mFeLl46C5InWwoMrN/Twenty?node-id=64918-248459&t=P3ogGJdLWsE1PlKk-4
https://www.figma.com/design/xt8O9mFeLl46C5InWwoMrN/Twenty?node-id=64918-246194&t=P3ogGJdLWsE1PlKk-4

Be careful to not superimpose background overlay even if clickOutside must work

[FelixMalfait]

"You will lose all your matching" sounds a bit akward. "mappings" maybe?