templater: show slightly better hint on map operation error It was super hard to find where the templater went wrong if a keyword was evaluated to '' or None.

templater: inline unwraphybrid() flatten() is the solo user of this function.

templater: drop hybrid-ness on unwrapvalue() Proxy methods are no longer necessary as list/dict functions go through the wrapped interface.

templater: mark .keytype as a private attribute

templater: abstract ifcontains() over wrapped types This allows us to make .keytype private. There's a minor BC that a hybrid dict/list of keytype=None now strictly checks the type of the needle. For example, {ifcontains(rev, files)} no longer matches a file named "1" at the rev=1. I made this change for consistency with the get(dict, key) function. We can restore the old behavior by making keytype=bytes the default if desired.

templater: inline wraphybridvalue() All wraphybridvalue() calls are now handled in the hybrid class.

templater: abstract min/max away I'm not certain how many get*() functions I'll add to the wrapped types, but getmin() and getmax() will allow us to optimize a revset wrapper.

stringutil: fix prettyrepr() to not orphan foo=<...> line