Connections: Support for custom icons

[dfalbel]

Addresses #6187

Add support for custom icons in the new connections pane.
The connections contract allows connections to provide a custom icon, which should be a full path to a squared png file.

This PR adds support for those icons in a few different places:

Release Notes

New Features

• Support for custom icons in the connections pane (Correctly render icons for connections that provide custom icons #6187)

Bug Fixes

• N/A

QA Notes

Not many packages support custom icons. I think the easiest setup is to use bigrquery:

library(DBI)

con <- dbConnect(
  bigrquery::bigquery(),
  project = "publicdata",
  dataset = "samples",
  billing = "gcp-project-id"
)

Where billing is a GCP project id.

HEre's another snippet that might be useful for reproducing:

install.packages("FactoMineR")
remotes::install_github("ColinFay/fryingpane")

library(fryingpane)
cook("FactoMineR")

@:connections

[github-actions]

E2E Tests 🚀
This PR will run tests tagged with: @:critical @:connections

^{readme  valid tags}

[softwarenerd]

Looks good. And, as we discussed on Zoom, I'd recommend moving any styles like:

<div className='col-icon' style={{ width: `${26}px` }}>

{icon ? <img src={icon} style={{ width: '26px', height: '26px' }}></img>

That are not being calculated in the .tsx file into the .css file for the component.

[softwarenerd]

LG!