[4.x] Prevent serialization errors with@nocache directive when using Blade view components

[duncanmcclean]

This pull request fixes a serialization error with the @nocache directive when using a Blade view component with a custom method.

This PR will evaluate any custom methods in Blade view components.

Fixes #8203.
Related: #6935

[jasonvarga]

Filtering out the variable prevents the error, but you are no longer able to use it.

// Layout.php

public function custom()
{
  return 'my custom var';
}

{{-- layout.blade.php --}}
@include('mypartial')

{{-- mypartial.blade.php --}}
{{ $custom }} // outputs "my custom var"

I used @include instead of @nocache there to show that it's supposed to work. If you use @nocache, without this PR it'll throw that serialization error, with this PR it'll throw undefined variable $custom.

I think instead of filtering them out, we should evaluate them. Then we can store the evaluated version in the context.

[duncanmcclean]

@jasonvarga Oops, I thought I had it working previously but I see the issue now. 🙈

I've updated this PR so it'll evaluate the values instead. I've also updated the PR title & description to better represent the changes.

[kgirzadas]

Before this change, in partials included using @nocache directive, I was accessing page data through $page variable (e.g. $page->some_field->handle()). After these changes, it no longer works because everything in the $page variable is converted to an array. Was this the expected effect?

[jasonvarga]

Was this the expected effect?

No, but I believe #9449 should resolve that.

[kgirzadas]

Was this the expected effect?

No, but I believe #9449 should resolve that.

I can confirm that the fix resolves the mentioned issue.