SCM Graph - Render code backticks

[bpasero]

Testing #229359

I think it would be nice to render code backticks in the graph view:

[lszomoru]

@kycutler, didn't you add markdown rendering to the tree recently? Would that work here as well?

[kycutler]

I added partial support -- at the moment it's just bold, italics, or strikethrough syntax that surround the entire string (basically the features that were already available internally, just not via API). It would take more work to support other styles or inline syntax not surrounding the entire string.