feat(many): default components to Phosphor Icons for ionic theme (#29617)

Issue number: internal

---------

## What is the current behavior?
Icons in the Ionic theme default to Ionicons.

## What is the new behavior?
- Renames the following config properties:
  - `datetimeShowMonthYearIcon` to `datetimeExpandedIcon`
  - `datetimeHideMonthYearIcon` to `datetimeCollapsedIcon`
  - `selectExpandIcon` to `selectExpandedIcon`
- Updates the icons for the `ionic` theme to the following Phosphor
Icons:

| Component | Config | Phosphor Icon | Font Weight |
| ------------------------ | --------------------------- |
----------------- | ----------- |
| Accordion | `accordionToggleIcon` | `CaretDown` | `regular` |
| Back Button | `backButtonIcon` | `CaretLeft` | `regular` |
| Breadcrumb | `breadcrumbSeparatorIcon` | `CaretRight` | `regular` |
| Breadcrumb | `breadcrumbCollapsedIcon` | `DotsThree` | `regular` |
| Checkbox | N/A | `Check` | `bold` |
| Checkbox (indeterminate) | N/A | `Minus` | `bold` |
| Datetime | `datetimeNextIcon` | `CaretRight` | `regular` |
| Datetime | `datetimePreviousIcon` | `CaretLeft` | `regular` |
| Datetime | `datetimeCollapsedIcon` | `CaretDown` | `regular` |
| Datetime | `datetimeExpandedIcon` | `CaretUp` | `regular` |
| Fab Button | `fabButtonCloseIcon` | `X` | `regular` |
| Input | `inputClearIcon` | `X` | `regular` |
| Input Password Toggle | `inputPasswordShowIcon` | `Eye` | `regular` |
| Input Password Toggle | `inputPasswordHideIcon` | `EyeSlash` |
`regular` |
| Item | `itemDetailIcon` | `CaretRight` | `regular` |
| Menu Button | `menuIcon` | `List` | `regular` |
| Reorder | `reorderHandleIcon` | `List` | `regular` |
| Refresher | `refreshingIcon` | ❌ | |
| Refresher (arrow icon) | N/A | `CaretLeft` | `fill` |
| Searchbar | `searchbarCancelIcon` | `ArrowLeft` | `regular` |
| Searchbar | `searchbarClearIcon` | `X` | `regular` |
| Searchbar | `searchbarSearchIcon` | `MagnifyingGlass` | `regular` |
| Select | `selectExpandedIcon` | `CaretDown` | `regular` |
| Select | `selectCollapsedIcon` | `CaretDown` | `regular` |
| Toggle | `toggleCheckedIcon` | `LineVertical` | `regular` |
| Toggle | `toggleUncheckedIcon` | `Circle` | `regular` |

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

core/src/components/checkbox/checkbox.ionic.scss

@@ -149,9 +149,7 @@ input {
 }
 
 .checkbox-icon path {
-  fill: none;
-  stroke: var(--checkmark-color);
-  stroke-width: var(--checkmark-width);
+  fill: var(--checkmark-color);
 
   opacity: 0;
 }

core/src/components/checkbox/checkbox.tsx

@@ -244,7 +244,8 @@ export class Checkbox implements ComponentInterface {
             <slot></slot>
           </div>
           <div class="native-wrapper">
-            <svg class="checkbox-icon" viewBox="0 0 24 24" part="container">
+            {/* Phosphor Icons define a larger viewBox */}
+            <svg class="checkbox-icon" viewBox={theme === 'ionic' ? '0 0 256 256' : '0 0 24 24'} part="container">
               {path}
             </svg>
           </div>
@@ -268,9 +269,11 @@ export class Checkbox implements ComponentInterface {
       );
     } else if (theme === 'ionic') {
       path = indeterminate ? (
-        <path d="M6.5 12H17.5" stroke-linecap="round" part="mark" />
+        // Phosphor Icon - minus bold
+        <path d="M228,128a12,12,0,0,1-12,12H40a12,12,0,0,1,0-24H216A12,12,0,0,1,228,128Z"></path>
       ) : (
-        <path d="M6 12.5L10 16.5L18.5 8" stroke-linecap="round" stroke-linejoin="round" part="mark" />
+        // Phosphor Icon - check bold
+        <path d="M232.49,80.49l-128,128a12,12,0,0,1-17,0l-56-56a12,12,0,1,1,17-17L96,183,215.51,63.51a12,12,0,0,1,17,17Z"></path>
       );
     }