Refactor existing Restbase gateway and extract shared logic into
shared Restbase provider. Also introduced new createNullModel()
which defines an empty preview model.
Additionally improve naming in new gateways/formatter so function
names are more explicity.
* Htmlize() became formatPlainTextExtract() as it should be used
only with plain text extracts
* removeEllipsis() became removeTrailingEllipsis() as it removes
only trailing ellipsis.
* src/gateway/index.js defines gateways by configuration name stored
in extension.json
Bug: T165018
Change-Id: Ibe54dddfc1080e94814d1562d41e85cb6b43bfc1
Depends-On: I4f42c61b155a37c5dd42bc40034583865abd5d7a
Page Previews should be able to consume HTML response generated by
MediaWiki. First we need to move out plain text crunching from
renderer.js and model.js. Mediawiki and Restbase gateways will have
to parse/htmlize plaintext into nice HTML by themselves.
Bug: T165018
Change-Id: I5d7e9f610bb809aa9fb035a4a9f96e9e8796c9d8
