fix(button): keep native submit or reset button in the dom for implicit form submission

[samrichardsontylertech]

PR Checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added/updated: N
• Docs have been added/updated: N
• Does this PR introduce a breaking change? N
• I have linked any related GitHub issues to be closed when this PR is merged? N

Describe the new behavior?

This adds a persistent slotted, hidden <button type="submit"></button> or <button type="reset"></button> to the base button component to enable implicit form submission, e.g. when a user presses the enter key while a form input is focused.