Utilities for overflow and object fit (#36848)

* Added "overflow-x" and "overflow-y"

- Having the same properties as overflow but for just the x and y axises
- Usecase being I want my y axis to be scrollable but not my x axis
- E.g a card with a vertical list of items.

* Added "object-fit" utilities

- The CSS object-fit property is used to specify how an <img> or <video> should be resized to fit its container.
- A responsive alternative to using background-img for a resizable fill/fit image.

* Updated documantation for the overflow utilities

- Now includes docs for `overflow-x` and `overflow-y` utilities

* Placeholder shortcode updated

- Can now choose to render an img tag or svg
- The image contains a base64 svg generated within the template
- example shortcode updated to detect, replace and render preview of 'img' tags as well

* New documentaion for Object Fit added

- Documentation added for the 'object-fit' util

* Updated spell checks issues

* Update object-fit.md

* Update overflow.md

* Update object-fit.md

* Updated markup to address HTML Validation Errors

- error: Bad value  for attribute "src" on element "img": Illegal character in scheme data: space is not allowed.
- info warning: Self-closing tag syntax in text/html documents is widely discouraged; it's unnecessary and interacts badly with other HTML features (e.g., unquoted attribute values). If you're using a tool that injects self-closing tag syntax into all void elements, without any option to prevent it from doing so, then consider switching to a different tool.

* Updated Fix

- Added Legibility to the img markup (example.html)
- Fixed issue with example not working properly (because image closing tag no longer has "/>" )

* update values by step of 0.25 in bundlewatch.config

The following values in .bundlewatch.config.json have been updated:
- ./dist/css/bootstrap-utilities.css
- ./dist/css/bootstrap-utilities.min.css
- ./dist/css/bootstrap.css
- ./dist/css/bootstrap.min.css

Co-authored-by: Daniel O <dobiekwe@byteworks.com.ng>
Co-authored-by: Mark Otto <otto@github.com>

scss/_utilities.scss

@@ -22,6 +22,20 @@ $utilities: map-merge(
       )
     ),
     // scss-docs-end utils-float
+    // Object Fit utilities
+    // scss-docs-start utils-object-fit
+    "object-fit": (
+      responsive: true,
+      property: object-fit,
+      values: (
+        contain: contain,
+        cover: cover,
+        fill: fill,
+        scale: scale-down,
+        none: none,
+      )
+    ),
+    // scss-docs-end utils-object-fit
     // Opacity utilities
     // scss-docs-start utils-opacity
     "opacity": (
@@ -40,6 +54,14 @@ $utilities: map-merge(
       property: overflow,
       values: auto hidden visible scroll,
     ),
+    "overflow-x": (
+      property: overflow-x,
+      values: auto hidden visible scroll,
+    ),
+    "overflow-y": (
+      property: overflow-y,
+      values: auto hidden visible scroll,
+    ),
     // scss-docs-end utils-overflow
     // scss-docs-start utils-display
     "display": (