⚠️ Rework completely how transitions works

- Use Svelte/Sapper native if and transitions to show either the page content or the loader, then load each page animationIn
- Code is safe on SSR side, using process.browser on this if
- The <main> element is on position absolute to fade nicely the different pages
- Code cleaning

src/molecules/Location.svelte

@@ -7,7 +7,7 @@
 </script>
 
 <div class="location">
-    <a href="/location/{country.slug}/{slug}" rel="prefetch" sapper-noscroll>
+    <a href="/location/{country.slug}/{slug}" rel="prefetch">
         <img src={country.flag.full_url} alt="Flag of {country.name}">
         <div class="anim-mask mask-city">
             <h3 class="location__city">{name}</h3>

src/molecules/Photo.svelte

@@ -46,7 +46,7 @@
 
     <div class="photo__image wrap">
         <div class="align">
-            <a href="/viewer/{location.country.slug}/{location.slug}/{photo.slug}" sapper-noscroll>
+            <a href="/viewer/{location.country.slug}/{location.slug}/{photo.slug}">
                 <picture class="photo__picture">
                     <source media="(min-width: 992px)" data-srcset={getThumbnail(private_hash, 1300)}>
                     <source media="(min-width: 768px)" data-srcset={getThumbnail(private_hash, 992)}>

src/molecules/Switcher.svelte

@@ -22,7 +22,7 @@
 
 <div class="switcher {type}">
     <div class="switcher__text" class:empty={!location}>
-        <a href="/" sapper-noscroll>
+        <a href="/">
             {#if !location}
             <span class="top">Houses</span>
             <span class="bottom">
@@ -36,7 +36,7 @@
     </div>
 
     <div class="button-control button-control--dashed switcher__icon">
-        <a href="/choose" aria-label="Change the location" sapper-noscroll>
+        <a href="/choose" aria-label="Change the location">
             <IconGlobe
                 color={type.includes('side') ? '#333' : '#fff'}
                 width={type.includes('side') ? 18 : 24}