Add details in instance update logs

Problem/Motivation

Following 📌 [1.0.0-alpha2] Better logs Active , we have this log message for instance update events:

"@instance has been updated" where :

• @instance is the label with summary of the instance's source

"@instance has been updated by @island" where:

• @instance is the label with summary of the instance's source
• @island is the label of the island plugin managing the 3rd party settings

Can we add a diff to detail the changes?

• "@instance has been updated: @diff"
• "@instance has been updated by @island: @diff"

Proposed resolution

When change is done within InstanceFormPanel, do we need to add a ::buildLogMessage() method to a UI Pattern's new or existing interface ?

For 3rd party settings, do we need a new InstanceUpdaterInterface with ::buildLogMessage() (or reusing the UI Patterns 2 one?) to be implemented by the same plugins already altering RenderableAltererInterface:

• UiSkinsPanel
• UiStylesPanel
• VisibilityConditionsPanel

Remaining tasks

Let's discuss first about the proposal. There is many things to discuss and decide here.

If we are OK, before coding anything, let's set together the diff message building rules for:

• ComponentSource
• BlockSource
• TokenSource
• WysiwygWidget
• UiSkinsPanel
• UiStylesPanel
• VisibilityConditionsPanel