Perf dashboard should have UI to set status on analysis tasks

Perf dashboard should have UI to set status on analysis tasks
https://bugs.webkit.org/show_bug.cgi?id=143977

Reviewed by Chris Dumez.

Added the UI to set the result of an analysis task to 'progression', 'regression', 'unchanged', and 'inconclusive'
as well as a boolean indicating whether creating the analysis task was the right thing to do or not.
The latter will be a useful metric once we start automatically creating analysis tasks.

* init-database.sql: Added two columns to analysis_tasks table.
* public/api/analysis-tasks.php: Include the added columns in the JSON.
* public/include/db.php:
(Database::to_database_boolean): Added.
* public/include/json-header.php:
(require_match_one_of_values): Added.
* public/privileged-api/update-analysis-task.php: Added. Updates 'result' and 'needed' values of an analysis task.
(main):
* public/v2/analysis.js:
(App.AnalysisTask.result): Added.
(App.AnalysisTask.needed): Added. We don't use DS.attr('boolean') here since that would coerce null into false
and we want to differentiate null from false in order to differentiate the null-ness of the value.
(App.AnalysisTask.saveStatus): Added.
(App.AnalysisTask.statusLabel): Use 'result' as the label if it's set and all build requests have been processed.
* public/v2/app.css:
* public/v2/app.js:
(App.AnalysisTaskController.analysisResultOptions): Added.
(App.AnalysisTaskController.shouldNotHaveBeenCreated): Added.
(App.AnalysisTaskController.needsFeedback): Added. Show the checkbox to indicate the analysis task should not have
been created if 'no change' is selected.
(App.AnalysisTaskController._updateChosenAnalysisResult): Added.
(App.AnalysisTaskController.actions.saveStatus): Added.
* public/v2/index.html: Extracted a partial template for updating the bug numbers. Also added the UI to update
'result' and 'needed' values of the analysis task.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@183041 268f45cc-cd09-0410-ab3c-d52691b4dbfc