Add Search all elements and search for an element in the parent.

[polivera]

Expand DOM element search functionality

This PR introduces SearchAll and SearchFromElement function to the page dom API.

Changes

Add SearchAll and SearchFromElement functions

Usage example

SearchAll

// Find all submit buttons on the page
output, err := page.SearchAll(ctx, &gopilot.PageSearchInput{
    Selector:     "button[type='submit']",
    Pierce:       true, // Include Shadow DOM
})
if err != nil {
    return err
}

for _, element := range output.Elements {
    // Interact with each element
}

SearchFromElement

// First, get a parent container
parentOutput, err := page.SearchAll(ctx, &gopilot.PageSearchInput{
    Selector: ".form-container",
})
if err != nil {
    return err
}

parent := parentOutput.Elements[0]

// Then search for a specific input within that container
inputOutput, err := page.SearchFromElement(ctx, parent, &gopilot.PageQuerySelectorInput{
    Selector: "input[name='email']",
})
if err != nil {
    return err
}

element := inputOutput.Element