Consider other settings to add to `BluespecSettings`

[RyanGlScott]

Currently, BluespecSettings only has a single option that can be configured:

copilot-bluespec/src/Copilot/Compile/Bluespec/Settings.hs

Lines 7 to 10 in 9d83645

	-- | Settings used to customize the code generated.
	newtype BluespecSettings = BluespecSettings
	{ bluespecSettingsOutputDirectory :: FilePath
	}

We may want to consider other options to add here. For example, do we want Bluespec equivalents of copilot-c99's cSettingsStepFunctionName? There are several function names that copilot-bluespec generates, and it might make sense to allow users to be able to change them.