Cheryl Strayed, as played by Reese Witherspoon in Jean-Marc Vallee’s “Wild,” is, bless the lord, not an easily discernible type. She’s also not the sort we’ve often encountered on the well-trod paths of female stereotypes in movies. Strayed is a bundle of messy imperfections, as we gradually learn from flashbacks that accumulate throughout her therapeutic journey on the Pacific Crest Trail in “Wild.”