[2.x] Load modal slot on show

[dillingham]

Problem:

Components within modals render when <jet-modal :show="false"> currently.

Effects:

• modals with components that request data on mount.. fires on page load
• modals with forms partially completed, closed, reopened.. not fresh form

Solution:

Adding v-if to the <slot> insures the the v-show still transitions but slot contents render each open

[driesvints]

Does this also happens on the Livewire side of things?