CTA: Add Center Top/Button Button Alignments

[AlexGStapleton]

Resolve #1637

[AlexGStapleton]

@Misplon What are your thoughts on adding an optional (due to the pre-existing nature of the widget) responsive collapse for the left and right alignments? We could call it... say, Mobile Button Layout (could also introduce a Tablet) and provide the following options:

• Standard/desktop Alignment.
• Above text.
• Below text.

I think it wouldn't be a bad idea to introduce it in this PR (unless it was to be merged really quickly) as it'll benefit from the top alignment and the LESS cleanup.

[Misplon]

Thanks, mate; yeah, agreed.

Let's re-think this slightly. Can we perhaps rename the setting to something like Alignment? How do you want to do this? Within a Responsive section?

• For Center Top and Center let's perhaps center the text.
• Do you want to remove the Mobile Align setting from the Button section? I'm not sure it does anything.

[AlexGStapleton]

Can we perhaps rename the setting to something like Alignment

We can do this, but we'll need to rename the center top/bottom settings as they don't really make sense when the setting is called Alignment.

Within a Responsive section?

I opted to add a single setting below the alignment setting. If we were to introduce other responsive settings a dedicated section may be worth it but with only a single one it's hard to justify.

[AlexGStapleton]

This PR could resolve #457 in its current state.