Add a toggle to run reporter._renderPageTree during build time

[Spawbreaker]

While working on a rather large site the reporter._renderPageTree that runs at the end of the build takes a significant number of lines in the console output. Cluttering the console, potentially hiding other issues.

Would it be possible to add this output to the Verbose log, or to add a configuration to toggle it on or off?

gatsby/packages/gatsby/src/commands/build.ts

Lines 576 to 581 in aa403a4

	reporter._renderPageTree({
	components: state.components,
	functions: state.functions,
	pages: state.pages,
	root: state.program.directory,
	})