added http request handler

Migrate from subscription providers to request handlers. Subscription providers are specific to subscriptions while request handlers are generic and can handle any type of query. This allows us use the same logic for both subscriptions and streamed queries (e.g. from stream and defer directives).

One core part of how request handler works is that it uses different strategies to handle multiple responses (default is auto which uses best guess approach).

Checks

[x] Ran yarn test-build
[x] Updated relevant documentations
[x] Updated matching config options in altair-static

Changes proposed in this pull request:

Todos

[x] HTTP request handler handle chunked data format
[x] Implement auto response stream handling strategy
[x] Settings for response.stream.strategy (auto, concatenate, append, patch)
[x] use new query result pane for subscriptions
[x] Deprecate existing subscriptions flow, and use request handlers for everything (create adapter from subscription providers to request handlers, especially from plugins)
[x] Switch loading indicator to bar
[x] Move loading cancellation to query results action
[x] Move tips into query result empty state(tips are one-line by default unless user clicks it)
[x] Update query result pane to handle multiple responses (can download individual responses)
[x] Update ExportWindowState
[x] cleanup unused css
[x] Tests
[ ] Add codemirror extension to highlight change in query result (later)
[ ] request handlers handle cURL command generation (later)

altair-graphql / altair

added http request handler #2550

Checks

Changes proposed in this pull request:

Todos