Enable a generalised way to access any warnings and/or error on BHoM load in any UI

[al-fisher]

From workshop on Excel - idea was mooted to enable access via Ribbon to any logged warnings - shown to user as an "exclamation mark" style feedback.

To avoid using a pop up with is more intrusive

@adecler suggested there is already some form of access via a "log" method in Reflection Engine.

To be formalised and then given access from each UI as appropriate

@adecler @awakeman