fix: allow <code> elements in TinyMCE (#2434)

This allows `<code>` elements to exist in the HTML used in the code snippet plugin. It has the `-` modifier to remove empty elements.

Co-authored-by: Wojciech Wróbel <[email protected]>

src/packages/tiny-mce/components/input-tiny-mce/input-tiny-mce.defaults.ts

@@ -10,7 +10,7 @@ export const UMB_BLOCK_ENTRY_WEB_COMPONENTS_ABSOLUTE_PATH = '@umbraco-cms/backof
 export const defaultFallbackConfig: RawEditorOptions = {
 	plugins: ['anchor', 'charmap', 'table', 'lists', 'advlist', 'autolink', 'directionality', 'searchreplace'],
 	valid_elements:
-		'+a[id|style|rel|data-id|data-udi|rev|charset|hreflang|dir|lang|tabindex|accesskey|type|name|href|target|title|class|onfocus|onblur|onclick|ondblclick|onmousedown|onmouseup|onmouseover|onmousemove|onmouseout|onkeypress|onkeydown|onkeyup],-strong/-b[class|style],-em/-i[class|style],-strike[class|style],-s[class|style],-u[class|style],#p[id|style|dir|class|align],-ol[class|reversed|start|style|type],-ul[class|style],-li[class|style],br[class],img[id|dir|lang|longdesc|usemap|style|class|src|onmouseover|onmouseout|border|alt=|title|hspace|vspace|width|height|align|umbracoorgwidth|umbracoorgheight|onresize|onresizestart|onresizeend|rel|data-id],-sub[style|class],-sup[style|class],-blockquote[dir|style|class],-table[border=0|cellspacing|cellpadding|width|height|class|align|summary|style|dir|id|lang|bgcolor|background|bordercolor],-tr[id|lang|dir|class|rowspan|width|height|align|valign|style|bgcolor|background|bordercolor],tbody[id|class],thead[id|class],tfoot[id|class],#td[id|lang|dir|class|colspan|rowspan|width|height|align|valign|style|bgcolor|background|bordercolor|scope],-th[id|lang|dir|class|colspan|rowspan|width|height|align|valign|style|scope],caption[id|lang|dir|class|style],-div[id|dir|class|align|style],-span[class|align|style],-pre[class|align|style],address[class|align|style],-h1[id|dir|class|align|style],-h2[id|dir|class|align|style],-h3[id|dir|class|align|style],-h4[id|dir|class|align|style],-h5[id|dir|class|align|style],-h6[id|style|dir|class|align|style],hr[class|style],small[class|style],dd[id|class|title|style|dir|lang],dl[id|class|title|style|dir|lang],dt[id|class|title|style|dir|lang],object[class|id|width|height|codebase|*],param[name|value|_value|class],embed[type|width|height|src|class|*],map[name|class],area[shape|coords|href|alt|target|class],bdo[class],button[class],iframe[*],figure,figcaption,cite,video[*],audio[*],picture[*],source[*],canvas[*]',
+		'+a[id|style|rel|data-id|data-udi|rev|charset|hreflang|dir|lang|tabindex|accesskey|type|name|href|target|title|class|onfocus|onblur|onclick|ondblclick|onmousedown|onmouseup|onmouseover|onmousemove|onmouseout|onkeypress|onkeydown|onkeyup],-strong/-b[class|style],-em/-i[class|style],-strike[class|style],-s[class|style],-u[class|style],#p[id|style|dir|class|align],-ol[class|reversed|start|style|type],-ul[class|style],-li[class|style],br[class],img[id|dir|lang|longdesc|usemap|style|class|src|onmouseover|onmouseout|border|alt=|title|hspace|vspace|width|height|align|umbracoorgwidth|umbracoorgheight|onresize|onresizestart|onresizeend|rel|data-id],-sub[style|class],-sup[style|class],-blockquote[dir|style|class],-table[border=0|cellspacing|cellpadding|width|height|class|align|summary|style|dir|id|lang|bgcolor|background|bordercolor],-tr[id|lang|dir|class|rowspan|width|height|align|valign|style|bgcolor|background|bordercolor],tbody[id|class],thead[id|class],tfoot[id|class],#td[id|lang|dir|class|colspan|rowspan|width|height|align|valign|style|bgcolor|background|bordercolor|scope],-th[id|lang|dir|class|colspan|rowspan|width|height|align|valign|style|scope],caption[id|lang|dir|class|style],-div[id|dir|class|align|style],-span[class|align|style],-pre[class|align|style],address[class|align|style],-h1[id|dir|class|align|style],-h2[id|dir|class|align|style],-h3[id|dir|class|align|style],-h4[id|dir|class|align|style],-h5[id|dir|class|align|style],-h6[id|style|dir|class|align|style],hr[class|style],small[class|style],dd[id|class|title|style|dir|lang],dl[id|class|title|style|dir|lang],dt[id|class|title|style|dir|lang],object[class|id|width|height|codebase|*],param[name|value|_value|class],embed[type|width|height|src|class|*],map[name|class],area[shape|coords|href|alt|target|class],bdo[class],button[class],iframe[*],figure,figcaption,cite,video[*],audio[*],picture[*],source[*],canvas[*],-code',
 	invalid_elements: 'font',
 	extended_valid_elements:
 		'@[id|class|style],+umb-rte-block[!data-content-udi],+umb-rte-block-inline[!data-content-udi],-div[id|dir|class|align|style],ins[datetime|cite],-ul[class|style],-li[class|style],-h1[id|dir|class|align|style],-h2[id|dir|class|align|style],-h3[id|dir|class|align|style],-h4[id|dir|class|align|style],-h5[id|dir|class|align|style],-h6[id|style|dir|class|align],span[id|class|style|lang],figure,figcaption',