merge ug3 core application changes

[benjaminmao123]

• LFPViewer

• Added Tooltip for channels so users can see channel names that are cut off.

• Increased margin to 100

• Fixed handleBroadcastMessage logic to support subselect for UG3 Electrode Viewer plugin.

• CoreServices

• Added methods to retrieve the processor by name/id

• Added method to retrieve predecessor processor ids

• DataBuffer

• Added an additional parameter to DataBuffer to store the timestampSampleIndex which is used by our Synchronizer plugin.

• Event

• Added an additional fillReferenceSampleEvent which is used by our Synchronizer plugin.

• GenericProcessor

• Added a method to set the reference sample for a block which is used by our Sychronizer plugin.

• RecordNode

• Added a method to override the record engine for testing

• BroadcastPayload

• Added a default constructor

• Added a getter for the payload.

[jsiegle]

It looks like there are going to be a ton of conflicts here. Instead of directly merging these two branches, can you copy and paste the relevant changes onto the latest development-juce8 branch?