bug: IonInput default autocapitalize value disrespects system keyboard settings and relevant browser defaults

https://github.com/ionic-team/ionic-framework/blob/88b701363c1865e81d7d136acab4b9fef3b1ab7a/core/src/components/input/input.tsx#L71

Setting `autocapitalize` to `'off'` by default results in `ion-input` and related components not respecting the system keyboard settings for autocapitalization and forces developers to explicitly set an overriding value on all ion-inputs, which itself might not respect system settings. Furthermore, this approach does not align with the default behavior of either of the primary OS browsers on which virtually all ionic apps are run.

If this property must necessarily have a default value, the reasonable solution would be to align with the default behavior of the primary OS browser defaults. https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes/autocapitalize
` • Chrome and Safari default to on/sentences`