[Textarea]: clearable by default, no default maxRows for autoGrow

[ly-tempel-bitweb]

Problem

1. The textarea always opts out of the form field's clear button (clearButton = false in textarea.component.ts), so it never shows one, even when clearable is set. Leaving textareas without a clear button was a deliberate choice, but that decision was recently changed. It's now a requirement that textareas are clearable like the other form field controls.

2. The autoGrow input maxRows defaults to 12, so an autoGrow textarea stops growing at 12 rows unless the consumer raises the limit.

Solution

1. Clear button

• A textarea inside a tedi-form-field shows a clear button by default, since clearable is already true by default.
• Consumers can opt out with <tedi-form-field [clearable]="false">.
• The button follows the same rules as other controls: it's hidden when the field is empty, disabled or read-only.
• Clicking it empties the value, updates the bound form control and moves focus back to the textarea.

2. autoGrow maxRows default

• maxRows has no default value (undefined).
• When maxRows isn't set, autoGrow has no row limit. maxHeight still caps the height if it's set.
• When maxRows is set, nothing changes.