feat(PanelTrigger): add icon override

[longmatthewh]

Adds 2 new optional props:

• expandedIcon
• collapsedIcon

This enables devs to use alternatives to the chevron-right and chevron-down icons.

Closes: #633

[github-actions]

Preview branch generated at https://feat-custom-paneltrigger-icons.d1gko6en628vir.amplifyapp.com

[scurker]

This needs documentation.

I'm not opposed to this change, but is this something that is in @awpearlm or @bobbyomari's designs?

[longmatthewh]

@scurker this was driven by a Monitor design where I'm using ExpandCollapsePanel for (notice the different icons)

[scurker]

@scurker this was driven by a Monitor design where I'm using ExpandCollapsePanel for (notice the different icons)

Thanks for the info! I just wanted to make sure this had designs behind it.

So the only thing missing is updating the docs page here. FYI I do think in the future the above pattern also will exist elsewhere so we will likely elevate it to its own pattern while the ExpandCollapsePanel provides the underlying functionality.

[longmatthewh]

@scurker docs have been updated

[github-actions]

Preview branch generated at https://feat-custom-paneltrigger-icons.d1gko6en628vir.amplifyapp.com