Enhancements related to current charts

[bunnyxt]

• 20201012, When display chart with huge items, it will cost tons of time to render, which will make page 'die' (cannot do anything, for example, click), maybe add rendering prompt would be great? or render in another thread, then display after render finished?
• 20201012, optionToConfig might still have many bugs, which not works according to my design. Although currently, it satisfied my limited requirements, it will broke out in the future. Refactor needed!
• 20201012, chart slide has bug! Should be fixed immediately after G2 4.1 release.
• 20201013, x axis date label always just show yy-dd format, which can be enhanced. For example, if all data in one day, it should show HH-mm format.
• 20201021, , separator should be added in tooltip value, which need new api of G2, see issue tooltip数值部分格式化设置配置 antvis/G2#2920.
• 20201028, add a switch to open or close speed display, select different prop to calc speed
• 20201028, add a switch to enable compare mode, just display two line separately in two different y axis
• 20201028, add a switch to enable only show one point per day to increase performance

[bunnyxt]

718c9ab

Partially finish No.4, use another approach to beautify x axis label of added.

[bunnyxt]

eb9b299

Finish No.5. See antvis/G2#2920 (comment)

[bunnyxt]

4783dff
Finish No.3.

[bunnyxt]

5c94dd8
Almost finish No.1.