Warning not emitted if word not in lexicon

[kwinkunks]

lexicon.get_component() should squawk if something is not found in the lexicon. Perhaps optionally silence with, eg, verbose=False

Weirdly, just setting 'required=True` in that function smits too many warnings, suggesting that something is broken in there. It should be ignoring case and I don't think it is.

As example, built striplog from las3 in Striplog_object notebook. 'Volcanic' should give a warning, but nothing else.