[Pipeline Viewer] Initial version follow-up work

[justinkambic]

Purpose

This issue tracks the follow-up work to the new Config View we're using to express Logstash configuration files in the Monitoring UI, merged in #18597.

• Additional work to refactor/remove unneeded code will follow this one. Breaking this work up is a conscious choice driven by a desire to segregate the scope of the changes. Tracked here: [Logstash] [Pipeline Viewer] Remove old pipeline viewer code #19736 Open: [Monitoring] [Pipeline Viewer] Remove obsolete code #20122
• We need to update the top-level nav, but it lives in Angular, so that will be a separate PR to Reactify that piece of the view, tracked here [Monitoring] [Logstash] Update pipeline top nav #18976
• The data the model classes give this view may end up changing, or we may need to modify the way the view behaves when displaying new pipelines, or dead pipelines [Logstash Monitoring] Pipeline Viewer shows 0s in the early life of a pipeline version #19429
• A proposed design element is the highlighting of nested statements, probably on a delayed hover. This would lower the opacity of outside statements. It's tracked here: Add outline highlighting to Config View #19463
• Refactor the CollapsibleStatement class to behave as a wrapper for props.children [Monitoring] [Pipeline Viewer] Refactor collapsible statement component to wrap props.children #19844 Open: [Pipeline Viewer] Refactor collapsible statement component to wrap props.children #20252
• Remove bare <img>s in favor of EuiIcons where possible Swap ad-hoc imgs for EUIIcons in Detail Drawer and Config View sub-components #20021 Open: [PipelineViewer] Replace bare img tags with euiicon #20330
• Add unit tests for Config View sub-components. Open: [PipelineViewer] Test PipelineViewer sub-components #20329
• Rename Config Viewer to use Pipeline Viewer name [Monitoring] [Logstash] [Pipeline Viewer] Rename Config Viewer to Pipeline Viewer #20123 Open: [Pipeline Viewer] [Monitoring] Rename config view to PipelineViewer #20230
• Fix typo in className prop Fix capitalization typo for className attribute. #20104

[chrisronline]

Removing monitoring so we can ensure our backlog is up to date. This work should be done by the logstash ui team