Make table border=none setting work

[map-r]

Suggested merge commit message (convention)

Fix (table): Changed default table and table cell properties to match the content styles. Fixes problem with setting border = none on the table. Closes #6841.

---

Additional details

Paste from Office test changes explanation

Aligned with actual data

<table class=MsoTableGrid border=1 cellspacing=0 cellpadding=0 width=597 style='border-collapse:collapse;mso-table-layout-alt:fixed;
border:none;
^^^^^^^^^
mso-border-alt:solid windowtext .5pt;mso-yfti-tbllook:1184;mso-padding-alt:
0cm 5.4pt 0cm 5.4pt'>

The first cell has a full border:

<td width="59%" style='width:59.0%;border:solid windowtext 1.0pt;mso-border-alt:
                                   ^^^^^^^^^^
solid windowtext .5pt;background:#CCCCCC;padding:0cm 5.4pt 0cm 5.4pt'>

While other cells have specific borders:

<td width="24%" style='width:24.0%;border:solid windowtext 1.0pt;
border-left:none;mso-border-left-alt:solid windowtext .5pt;mso-border-alt:solid windowtext .5pt;
^^^^^^^^^^^^^
background:#CCCCCC;padding:0cm 5.4pt 0cm 5.4pt'>

[map-r]

@DawidKossowski Outro for this task/PR:

as @oleq validly pointed out deeper problems with how we treat default values in config vs in styles and what should we do with customizing them in a valid priority - you can at least see it in the comments here #14921 (comment)

[Witoso]

We need to make the change in a different place:

ckeditor5/packages/ckeditor5-table/src/utils/table-properties.ts

Lines 100 to 108 in 08270aa

	const normalizedConfig: NormalizedDefaultProperties = {
	borderStyle: 'none',
	borderWidth: '',
	borderColor: '',
	backgroundColor: '',
	width: '',
	height: '',
	...config
	};