arccore.filter bug in filter spec directive quanderscore parsing

[ChrisRus]

re: @encapsule/arccore v0.1.6 "grasslands" https://www.npmjs.com/package/@encapsule/arccore

I was writing a large filter spec and noticed something odd in the way that filter parses filter spec directives (e.g. quanderscore-prefixed filter spec namespace descriptor object properties).

This is nonsense!

Error: Filter factory failure: While examining data namespace '~.outputFilterSpec.evalFrames.evalFrameDescriptor.frameEvalResults.frameEvalSummary.transitions.cdsDataPath': Unrecognized typemap directive '___________________________________________________whatever' not allowed in declaration.

I haven't looked at the code but am sure that I incorrectly determine that the property name starts with four underscores and then but neglected to account for some idiot (me - I found it) using more than four underscore.

This is very unlikely to impact very many people. However, filter should correctly parse quanderscore directives correctly to ensure that the FSP produces the correct error message in all cases.