fix(ls): fix descriptions in --long human output

[jbrobst]

Having arborist's loadActual use a hidden lockfile caused a lot of the information in actual package.json files to not be available in the tree, some of which is relied upon by cli commands like ls --long to output descriptions. This was fixed for npm query in #5263 by adding an option to avoid the hidden lockfile, forceActual. So, use this option for ls --long as well.

Additionally, ls --long's unconditional access of node.package.description errors when node.package is undefined (#5961). This happens when node is not an arborist node but rather an object created by mapEdgesToNodes representing a missing linked node. Address this by making description output conditional on node[_missing], as was similarly done for ls --json --long in 2aecec5.