Change default collectors, aggregate messages

[barryvdh]

So let's think about which collectors are added by default, and which need to be extracted to a separate package.

I understand you want to keep this repo as 'clean' as possible, but there is something to be said for some default collectors:

• MessagesCollectors, can aggregate other message collectors. So it could be the starting point for other plugins, they can just add messages without the need for a new tab. (See the LoggerCollector that is now added as example)
• MagentoCollector, some basic info (version/locale) as icons in the toolbar.
• TimeDataCollector, can be used to measure things, eg. run measurements in your plugin, start/stop events etc. Some as for messages, this can be a common tab where all these are added. (Also adds a request timer to show the time it took, mostly useful in production)

Separate developer collectors (to be extracted):

• LoggerCollector; while perhaps more useful for Developers, it is the default way to show info/debug messages, so could also be a very useful default to add by default.
• EventsCollector; log all events + params
• ProfilerCollector; register as profiler with timingdata.
• ExceptionCollector; show exceptions + stacktrace when added via the Logger (perhaps also catch other exceptions?)
• RequestCollector; show the global information from the request. Could be upgraded to use the Magento Request object.

Possible extra developer collectors:

• Route/Controller information; show which module/route etc is shown
• Layout: show why a layout is chosen (theme/locale/updates etc)
• Templates/blocks, show which templates ( + path) is being used to generate the output
• Config; show some configuration settings that can be important.
• Queries; log all queries with parameters.
• Mails/queue: track which mails are sent to qeue (or all queued events?)
• ...

[barryvdh]

I extracted the collectors to my own extension; https://github.com/fruitcake/magento2-developer-toolbar

I added an AbstractCollector here, so de-duplicate code from the collectors.

@elzekool This good to merge?

[barryvdh]

Although perhaps we should add the 'default' datacollectors also by means of plugins, with a higher sortOrder. Eg. start the collectors with 100, 110, 120, so collectors can be added in front/between.

[elzekool]

@barryvdh Yeah perfect! I merged it