BUGFIX Rewrite of internal node properties in FlowQueries

[dlubitz]

Also fixed existing and added missing tests.

• _contextPath
• _depth
• _hiddenInIndex
• _path

[kitsunet]

Just wondering, this is obviously wrong but we need both, right? you could have q(node).property('_depth_) as well as node._depth or do we cover that elsewhere?

[dlubitz]

We have always two cases: node.depth and also q(node).property('depth')

The code was already trying to handle that, but unfortunatelly, the regex we used was missing the q(...) part, so we tried to replace all node.property(...) which is actally not valid.

[dlubitz]

Thanks for your input @kdambekalns. I've changed it.

[mhsdesign]

Thanks so much and sorry for all the requested adjustments