10+ lines Aria blatantly disregarded which destroyed question integrity

Summary:
In the passage widget, I forgot to add the starting line number
to the line numbers returned via getReference for passage-refs
(since we add that to the actual displayed line numbers).

This commit adds this.state.startLineNumbersAfter appropriately.

Test Plan:
Open
[this item](http://localhost:9000/test.html#content=%7B%22question%22%3A%7B%22content%22%3A%22%5B%5B%E2%98%83%20passage%202%5D%5D%5Cn%5Cn%5B%5B%E2%98%83%20passage%201%5D%5D%5Cn%5Cn%5B%5B%E2%98%83%20passage-ref%201%5D%5D%22%2C%22images%22%3A%7B%22https%3A%2F%2Fka-perseus-graphie.s3.amazonaws.com%2Fda8df81c78b22f5c69d477d8eabfb583968eaf84.png%22%3A%7B%22width%22%3A400%2C%22height%22%3A70%7D%2C%22https%3A%2F%2Fka-perseus-graphie.s3.amazonaws.com%2Fb59fc02ca1aae800977b8793ed22f647a1aa75ee.png%22%3A%7B%22width%22%3A425%2C%22height%22%3A150%7D%7D%2C%22widgets%22%3A%7B%22passage%202%22%3A%7B%22type%22%3A%22passage%22%2C%22graded%22%3Atrue%2C%22options%22%3A%7B%22passageTitle%22%3A%22%22%2C%22passageText%22%3A%22Lorem%20Ipsum%20is%20simply%20dummy%20text%20of%20the%20printing%20and%20typesetting%20industry.%20Lorem%20Ipsum%20has%20been%20the%20industry%27s%20standard%20dummy%20text%20ever%20since%20the%201500s%2C%20when%20an%20unknown%20printer%20took%20a%20galley%20of%20type%20and%20scrambled%20it%20to%20make%20a%20type%20specimen%20book.%20It%20has%20survived%20not%20only%20five%20centuries%2C%20but%20also%20the%20leap%20into%20electronic%20typesetting%2C%20remaining%20essentially%20unchanged.%20It%20was%20popularised%20in%20the%201960s%20with%20the%20release%20of%20Letraset%20sheets%20containing%20Lorem%20Ipsum%20passages%2C%20and%20more%20recently%20with%20desktop%20publishing%20software%20like%20Aldus%20PageMaker%20including%20versions%20of%20Lorem%20Ipsum.%5Cn%22%2C%22footnotes%22%3A%22%22%2C%22showLineNumbers%22%3Atrue%7D%2C%22version%22%3A%7B%22major%22%3A0%2C%22minor%22%3A0%7D%7D%2C%22passage%201%22%3A%7B%22type%22%3A%22passage%22%2C%22graded%22%3Atrue%2C%22options%22%3A%7B%22passageTitle%22%3A%22%22%2C%22passageText%22%3A%22It%20is%20a%20long%20established%20fact%20that%20a%20reader%20will%20be%20distracted%20by%20the%20readable%20content%20of%20a%20page%20when%20looking%20at%20its%20layout.%20The%20point%20of%20using%20Lorem%20Ipsum%20is%20that%20it%20has%20a%20more-or-less%20normal%20distribution%20of%20letters%2C%20as%20opposed%20to%20using%20%27Content%20here%2C%20content%20here%27%2C%20%7B%7B__making%20it__%7D%7D%20look%20like%20readable%20English.%20Many%20desktop%20publishing%20packages%20and%20web%20page%20editors%20now%20use%20Lorem%20Ipsum%20as%20their%20default%20model%20text%2C%20and%20a%20search%20for%20%27lorem%20ipsum%27%20will%20uncover%20many%20web%20sites%20still%20in%20their%20infancy.%20Various%20versions%20have%20evolved%20over%20the%20years%2C%20sometimes%20by%20accident%2C%20sometimes%20on%20purpose%20%28injected%20humour%20and%20the%20like%29.%5Cn%22%2C%22footnotes%22%3A%22%22%2C%22showLineNumbers%22%3Atrue%7D%2C%22version%22%3A%7B%22major%22%3A0%2C%22minor%22%3A0%7D%7D%2C%22passage-ref%201%22%3A%7B%22type%22%3A%22passage-ref%22%2C%22graded%22%3Atrue%2C%22options%22%3A%7B%22passageNumber%22%3A1%2C%22referenceNumber%22%3A1%7D%2C%22version%22%3A%7B%22major%22%3A0%2C%22minor%22%3A0%7D%7D%7D%7D%2C%22answerArea%22%3A%7B%22type%22%3A%22multiple%22%2C%22options%22%3A%7B%22content%22%3A%22%22%2C%22images%22%3A%7B%7D%2C%22widgets%22%3A%7B%7D%7D%2C%22calculator%22%3Afalse%7D%2C%22itemDataVersion%22%3A%7B%22major%22%3A0%2C%22minor%22%3A1%7D%2C%22hints%22%3A%5B%5D%7D)
before and after this change.

See that it shows "line 5" before this change, but "line 15" afterwards.

Auditors: michelle