fix: Improve contextual spacing for JSX expression containers when js…

[AaronLieberman]

…xExpressionContainer.spaceSurroundingExpression: true

When jsxExpressionContainer.spaceSurroundingExpression is true, make sure the spaces around braces are right based on the context of where the brace lies.

The change is to only add the space if the open brace is not at the end of a line. We do that on the opening brace by adding a Signal::SpaceOrNewLine which allows the system to add the space if it needs to for purposes of word wrap, otherwise ommitting it. For the close brace, we add the space if we're not the first token on the line.

The impetus for this was the case where an opening brace within a JSX element was the last character on a line, or a closing brace was the first. For example:

	<OuterComponent
		inner={
			<InnerComponent
				item={ content }
				className={ styles.someClass }
				foo={ areallylongidentifier }
				bar={ anotherreallylongidentifier }
			/>
		}
	/>;

The above case was getting formatted with extra spaces around the braces for the "inner" attribute.

This fixes this case and similar ones, plus adds additional varied test cases to cover variations of this idea.