[Layout foundations] Adjust size and position of title and body in SkeletonPage to closer match Page (#8030)

<!--
  ☝️How to write a good PR title:
- Prefix it with [ComponentName] (if applicable), for example: [Button]
  - Start with a verb, for example: Add, Delete, Improve, Fix…
  - Give as much context as necessary and as little as possible
  - Prefix it with [WIP] while it’s a work in progress
-->

### WHY are these changes introduced?

Fixes #8014 <!-- link to issue if one exists -->

<!--
  Context about the problem that’s being addressed.
-->

### WHAT is this pull request doing?

- Centers `SkeletonTitle` to align with `PrimaryActionSkeleton` on right
- Reduces height of `SkeletonTitle` from `28px` to `24px` to closer
match `Page` title
- Removes `paddingBlockStart` from `SkeletonPage` Body allowing it shift
up vertically matching `Page`

Before|
:----:|
<img width="1007" alt="Screenshot 2023-01-11 at 3 48 06 PM"
src="https://user-images.githubusercontent.com/59836805/211915956-c9ee9f44-e1c5-4e65-a91f-44678caf4f31.png">|
**After**|
<img width="1024" alt="Screenshot 2023-01-11 at 3 47 40 PM"
src="https://user-images.githubusercontent.com/59836805/211916089-707a3af2-fb1f-4046-90bc-cb362bed2162.png">|

<!--
  Summary of the changes committed.

Before / after screenshots are appreciated for UI changes. Make sure to
include alt text that describes the screenshot.

If you include an animated gif showing your change, wrapping it in a
details tag is recommended. Gifs usually autoplay, which can cause
accessibility issues for people reviewing your PR:

    <details>
      <summary>Summary of your gif(s)</summary>
      <img src="..." alt="Description of what the gif shows">
    </details>
-->

<!-- ℹ️ Delete the following for small / trivial changes -->

### How to 🎩

[Spin
Link](https://admin.web.web-6ubu.chaz-dean.us.spin.dev/store/shop1/)

<!--
  Give as much information as needed to experiment with the component
  in the playground.
-->

### 🎩 checklist

- [ ] Tested on
[mobile](https://github.com/Shopify/polaris/blob/main/documentation/Tophatting.md#cross-browser-testing)
- [ ] Tested on [multiple
browsers](https://help.shopify.com/en/manual/shopify-admin/supported-browsers)
- [ ] Tested for
[accessibility](https://github.com/Shopify/polaris/blob/main/documentation/Accessibility%20testing.md)
- [ ] Updated the component's `README.md` with documentation changes
- [ ] [Tophatted
documentation](https://github.com/Shopify/polaris/blob/main/documentation/Tophatting%20documentation.md)
changes in the style guide

Author: chazdean

.changeset/fluffy-hotels-explain.md

@@ -0,0 +1,5 @@
+---
+'@shopify/polaris': patch
+---
+
+Updated `SkeletonPage` title and body layout

polaris-react/src/components/SkeletonPage/SkeletonPage.tsx

@@ -41,7 +41,7 @@ export function SkeletonPage({
       <Box
         background="surface-neutral"
         minWidth="120px"
-        minHeight="28px"
+        minHeight="24px"
         borderRadius="base"
       />
     </div>
@@ -77,25 +77,18 @@ export function SkeletonPage({
       >
         <AlphaStack gap="0" fullWidth>
           <Box
-            padding={{xs: '4', md: '5'}}
-            paddingBlockEnd={{xs: '2', md: '5'}}
-            paddingInlineStart={{sm: '0'}}
-            paddingInlineEnd={{sm: '0'}}
+            paddingBlockStart={{xs: '4', md: '5'}}
+            paddingBlockEnd={{xs: '4', md: '5'}}
+            paddingInlineStart={{xs: '4', sm: '0'}}
+            paddingInlineEnd={{xs: '4', sm: '0'}}
           >
             {breadcrumbMarkup}
-            <Inline align="space-between" blockAlign="start">
+            <Inline align="space-between" blockAlign="center">
               {titleContent}
               {primaryActionMarkup}
             </Inline>
           </Box>
-          <Box
-            paddingBlockStart={{xs: '2', md: '5'}}
-            paddingBlockEnd="2"
-            paddingInlineStart="0"
-            paddingInlineEnd="0"
-          >
-            {children}
-          </Box>
+          <Box paddingBlockEnd="2">{children}</Box>
         </AlphaStack>
       </Box>
     </AlphaStack>