Handle interrupts in table row

[alexcoco]

tablerow behaves very similarly to a for loop but does not handle interrupts. Interrupts in the BlockBody of a Tablerow tag will stop rendering the block body but will continue to loop through the entire collection, even with pending interrupts. This is because Tablerow does not check for and pop interrupts.

The effect of this is the full collection will be iterated and it's possible, if the first node in the Tablerow's body is a continue or break, that the interrupts keep stacking (since BlockBody only checks interrupts after rendering the node). This behaviour can lead to causing outer loops to prematurely exit due to stacked/leaked interrupts.

In this PR, I propose we treat Tablerow like a loop which means it needs to pop and handle interrupts. continue interrupts are popped but ignored because we still want to output the appropriate </tr> strings before continuing to the next iteration.

This is a small behaviour change that would shift handling interrupts inside Tablerow bodies to the Tablerow itself instead of a For loop that may enclose it. That said, I believe this is the more expected behaviour.

[alexcoco]

Output before my changes:

"<tr class=\"row1\">
<td class=\"col1\"></td><td class=\"col2\"></td><td class=\"col3\"></td></tr>
"

You can see that all three table row iterations occur and the outer loops are exited.