Fix context swtich in block hooks

[robcxyz]

Block hooks currently create a new context that loses the reference to the main output_dict during execution and the output is then inserted into a key. This works and has the added advantage of maintaining a new context keyed on the level that the parsing is done but this makes it impossible to set keys outside of the block context.

Would be nice if we had the best of both worlds, the context on the same level of the block but also as the block is parsed, the output is put directly into the top level output_dict. If this was the case, the output_dict of the block hook could be the same but you would need to have some carved out logic for setting keys to be able to insert based on a new key path.

WIP issue...