Split event handling and chrome.storage saving in extensions options …

[trek]

Description

Extracting a bit of code from a larger piece of work to make it more reviewable.

For the extensions modal below:

This PR splits the event handling toggling the Tomster icon from its persistence to chrome.storage. This is required because of the shape of what we store.

This shape:

{
  options: {
    showTomster: true
  }
}

means that any update to other values we'd like to store in options must be merged with any existing values we want to retain. It's not been a problem so for because we're only saving a single value. However, if we add another option (the proposed selectedEditor) and don't first grab the stored options, we'd blow them away.

We could go with a structure like

{
  options: {
    showTomster: true
  },
  selectedEditor: <whatever value here>
}

and skip the round-tripping / merge and use a pattern where the event handler also stores, but I wasn't sure if we wanted to add more properties to the root object stored or wanted to keep that clean and store all things

[NullVoxPopuli]

much better API, nice work