fix: handle consecutive escapes for splitAccessPath

[suchanlee]

There was a bug in splitAccessPaths where if there were consecutive \\s it would skip a character due to an extra increment in the index

For example:

• \\a\\b\\c -> a\\bc (which is wrong but perhaps harmless)
• \\[\\"foo\\"\\] -> Access path missing open bracket error due to skipping the last \\ following \\" and getting in the ] conditional although it's been escaped

Added tests for these cases

[suchanlee]

Thanks a bunch for approving! What's the process for getting it merged?

[domoritz]

@jheer usually merges and releases at some point. If you need this in your package now, I recommend patching the package dependency.

[jheer]

Thanks!