refactor: input value getters and setters (CP: 14)

[mukherjeesudebi]

Description

Backports the following PRs:

• refactor: move input value getters and setters to InputMixin web-components#5586

Part of vaadin/web-components#5763

[vursen]

The new getter/setter could be also used here:

vaadin-text-field/src/vaadin-number-field.html

Line 289 in 7e03465

this.value = this.inputElement.value = String(parseFloat(value));

vaadin-text-field/src/vaadin-text-area.html

Line 290 in 7e03465

const match = this.inputElement.value.match(this.pattern);

[vursen]

And also here:

vaadin-text-field/src/vaadin-text-area.html

Line 284 in 7e03465

if (!this.pattern || !this.inputElement.value) {