[TabLayout] Add Padding to TabItems

Is your feature request related to a problem? Please describe.
We need to be able to add extra padding between the Tab Item content and the Tab Indicator. Currently there does not seem to be an exposed way to set the padding to be used for TabItems.

Describe the solution you'd like

Expose a way to set a particular padding style for the text and be able to set a default for the tab padding. I notice there is a TabLayout_tabInlineLabel, but there is no documentation on how this works or if it will even do what we want to do.

Describe alternatives you've considered
We've considered manually including the tabItems in the tablayout layout file, and then setting margins or padding, but this doesn't work well for programmatically adding tabs.

Inizia con le API di TabLayout e TabItem, quindi esamina l’attributo TabLayout_tabInlineLabel e l’approccio basato su un file di layout menzionato nell’issue. Il lavoro è completato quando i chiamanti possono configurare il padding del testo delle tab e impostare un padding predefinito per le tab, incluse quelle aggiunte programmaticamente.