Contextual search in the generic vizier search box

(e.g. say “-nebulae” etc)
Uses the “-source={keyword}” instead of “-kw={keyword}”

the keywords are the same as in the new ADS api

Start by locating the generic Vizier search box and the current handling of the -kw={keyword} syntax. Compare the supported keywords with the new ADS API keywords, then verify that contextual inputs such as -nebulae are accepted and translated to -source={keyword}. Done means the supported contextual searches work through the generic Vizier search interface.

Written by the indexing model from the issue text.