Terminal: The user should be able to zoom a pane

[zadjii-msft]

The user should be able to zoom a pane, to make the pane take the entire size of the terminal window temporarily. Pressing the shortcut again on a zoomed pane will return to the unzoomed state

[zadjii-msft]

Okay so one of the outstanding questions with this feature - how do we indicate to the user _visually_ that the tab has a zoomed pane?

tmux does it with a Z in the window title:

I've heard it suggested that maybe we should manually enable the focus border around all the edges of the window. Personally, I hate that.
 

Maybe if we stuck this icon in the TabViewItem:

| E8A3 | ZoomIn
-- | -- | --

we could either:

• replace the tab's icon with the ZoomIn icon
• Insert the ZoomIn icon at the start of the tab's name

Thoughts?

[zadjii-msft]

Proof-of-concept:

Need to document some methods and add comments throughout, but this is what we discussed in our team sync today. Note that the zooming takes a while because it's resizing and this is a debug build, so resizing is S L O W

[msftbot[bot]]

:tada:This issue was addressed in #6989, which has now been successfully released as Windows Terminal Preview v1.3.2382.0.:tada:

Handy links:

• Release Notes
• Store Download

[msftbot[bot]]

:tada:This issue was addressed in #6989, which has now been successfully released as Windows Terminal v1.4.3141.0.:tada:

Handy links:

• Release Notes
• Store Download

[msftbot[bot]]

:tada:This issue was addressed in #6989, which has now been successfully released as Windows Terminal Preview v1.5.3142.0.:tada:

Handy links:

• Release Notes
• Store Download