gracedb-2.30.0

Changes in this release:

• Improve responsiveness of GWTC GETs (!247 (merged))
• Decrease load time of Public Alerts page (!245 (merged))
• Improve event query and serialization performance (!243 (merged))
  • See #3 (closed) in this comment regarding changes to the event igwn-alert packet.
  • See this comment regarding including null values in SingleInspiral serializations
• Improve superevent query and serialization performance (!246 (merged))
• Return truncated results and warning message to users making large browser queries (!248 (merged))
• Tweak look and feel of main search page (1b9caed1)