Previously, the default open tab could only be selected by not
providing the state query. Add support for selecting the default
open tab with an explicit ?state=open query too.

Similar to https://github.com/shurcooL/issuesapp/commit/0b82558264994ab993533eed0d2cfe83e145dbe5.

Apply this change to make the change rename event easier to read.

Follows https://github.com/shurcooL/issuesapp/commit/a359f164dfa502a21cdc4cc3582a5b4221308d2a.

These events have been superseded by change.Review and its State field,
and removed from the change package. Delete support for them.

Follows https://dmitri.shuralyov.com/service/change/...$commit/9a7a6e8aef50bf7dceb93c681ed6446f3fdfa0b0.

Improve naming consistency.

Similar to https://github.com/shurcooL/issuesapp/commit/3bc17d8bc061b5a11eb287a91e23ef5dfcc38ea4.

Follows https://dmitri.shuralyov.com/service/change/...$commit/5b675ebb0b2bc6dd93ba2cedf6b4c7c9e0271de1
and https://dmitri.shuralyov.com/html/belt/...$commit/f6fb90ff73e49d9904a6a8a5561e437734a2ea57.

This helps readability, and doesn't make the page appear too wide on
narrow mobile displays.

Helps https://dmitri.shuralyov.com/app/changes/...$issues/1.

Follows https://dmitri.shuralyov.com/service/change/...$commit/0493202ef5f73b299291d6aa0ad2f5338c197e46.