Align Span Operations with new spec

[AbhiPrasad]

As per getsentry/develop#694, we should align on span operations across our SDKs

SDK	Old Operation	New Operation	Link	PR
Laravel
	laravel.handle	middleware.handle	https://github.com/getsentry/sentry-laravel/blob/afe35677784415dbbabd9d6be626948d739fc8aa/src/Sentry/Laravel/Tracing/Middleware.php#126
	laravel.bootstrap	app.bootstrap	sentry-laravel/src/Sentry/Laravel/Tracing/Middleware.php Line 147 in afe3567 $spanContextStart->setOp('laravel.bootstrap');
	laravel.autoload	app.php.autoload	sentry-laravel/src/Sentry/Laravel/Tracing/Middleware.php Line 171 in afe3567 $autoload->setOp('laravel.autoload');
	laravel.view	view.render	sentry-laravel/src/Sentry/Laravel/Tracing/ViewEngineDecorator.php Line 39 in afe3567 $context->setOp('laravel.view');