Optimise query results

[artemmufazalov]

Currently on very big datasets in results or with big request stats some use cases are very slow and could take up to 2-3 seconds 😱. Big stats are quite a common thing for requests with multi schema.

Use cases:

1. Switching from History or Saved tab to Query tab if there are some results
2. Switching to results from stats and vice versa

What could be done:

1. Keep rendered elements on screen (for example with display: none), so they won't be calculated again. Applicable to result tables, stats, ast, explain plan and Fullscreen component
2. Optimise data calculations and rendering

Migrating QueryEditor files to TS is essential for this issue: #619

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Inspired by: #595 (comment)

[antonkovalenko]

@Raubzeug please link this one to a ticket about migration

[Raubzeug]

@antonkovalenko I've double checked the situation, and it still needs some improvements.
Huge tables are re-rendering every time we return to the tab with results (or switch to Fullscreen). Let's evaluate this issue as is.

[antonkovalenko]

@Raubzeug please add a screencast and a new issue about json inspector #1388

[artemmufazalov]

Query result table optimization

With dynamicRenderType: 'variable' and dynamicItemSizeGetter table renders all its cells, it causes performance issues on big tables.

Rendering of a query result table with 100 000 rows.

With dynamicRenderType: 'variable' and dynamicItemSizeGetter:

With 'uniform' rendering:

I'm not sure what is exactly the key reason here, it may be dynamicItemSizeGetter which makes react-list check hasDeterminateSize to be true (https://github.com/caseywebdev/react-list/blob/master/react-list.es6#L246) or it may be 'variable' render type itself