Reduce security & spaces plugin bundle sizes

[mshustov]

The current bundle sizes:
security.plugin.js - 2.7Mb
spaces.plugin.js - 1.8Mb

We can reduce the size by adding lazy loading for management section components.

kibana/src/plugins/management/public/types.ts

Line 59 in 8e17fda

mount: ManagementSectionMount;

Kibana loading performance in one of the critical problems to address in the current release. Let me know if you manage to squeeze the issue in the remaining time until FF. Otherwise, I can help to implement it.
Useful links https://github.com/elastic/kibana/blob/master/src/core/MIGRATION.md#how-to-understand-how-big-the-bundle-size-of-my-plugin-is

[elasticmachine]

Pinging @elastic/kibana-security (Team:Security)

[azasypkin]

ACK: taking a look at the Security plugin management sections first, as they have a bigger impact.

[azasypkin]

I believe we've made reasonable improvements during last couple of weeks and we can close this issue for now. We'll try to track bundle sizes on a constant basis until we get automation for that.

Here is what we have in master now:

• Spaces plugin:

- 456K - spaces.plugin.js
-  60K - spaces.plugin.js.br
-  77K - spaces.plugin.js.gz
- 178K - 1.plugin.js
-  23K - 1.plugin.js.br
-  28K - 1.plugin.js.gz
-  41K - 2.plugin.js
- 6.2K - 2.plugin.js.br
- 7.4K - 2.plugin.js.gz
-  42K - 3.plugin.js
- 7.3K - 3.plugin.js.br
- 8.2K - 3.plugin.js.gz
- 102K - 4.plugin.js
-  15K - 4.plugin.js.br
-  20K - 4.plugin.js.gz
- 7.3K - 5.plugin.js
- 2.1K - 5.plugin.js.br
- 2.4K - 5.plugin.js.gz

• Security plugin

- 269K - security.plugin.js
-  43K - security.plugin.js.br
-  51K - security.plugin.js.gz
- 175K - 0.plugin.js
-  41K - 0.plugin.js.br
-  48K - 0.plugin.js.gz
-  25K - 1.plugin.js
- 4.2K - 1.plugin.js.br
- 4.7K - 1.plugin.js.gz
- 617K - 3.plugin.js
-  56K - 3.plugin.js.br
-  82K - 3.plugin.js.gz
- 178K - 4.plugin.js
-  18K - 4.plugin.js.br
-  23K - 4.plugin.js.gz
- 178K - 5.plugin.js
-  23K - 5.plugin.js.br
-  29K - 5.plugin.js.gz
-  44K - 6.plugin.js
- 6.9K - 6.plugin.js.br
- 7.7K - 6.plugin.js.gz
-  41K - 7.plugin.js
- 6.2K - 7.plugin.js.br
- 7.4K - 7.plugin.js.gz
-  61K - 8.plugin.js
- 9.7K - 8.plugin.js.br
-  12K - 8.plugin.js.gz
-  35K - 9.plugin.js
- 5.9K - 9.plugin.js.br
- 6.9K - 9.plugin.js.gz
-  32K - 10.plugin.js
- 5.5K - 10.plugin.js.br
- 6.6K - 10.plugin.js.gz
-  35K - 11.plugin.js
- 6.4K - 11.plugin.js.br
- 7.6K - 11.plugin.js.gz
-  42K - 12.plugin.js
- 7.3K - 12.plugin.js.br
- 8.2K - 12.plugin.js.gz
-  39K - 13.plugin.js
- 8.1K - 13.plugin.js.br
- 9.1K - 13.plugin.js.gz
-  29K - 14.plugin.js
- 4.8K - 14.plugin.js.br
- 5.4K - 14.plugin.js.gz
- 102K - 15.plugin.js
-  15K - 15.plugin.js.br
-  20K - 15.plugin.js.gz
-  32K - 16.plugin.js
- 5.9K - 16.plugin.js.br
- 6.6K - 16.plugin.js.gz
-  23K - 17.plugin.js
- 4.9K - 17.plugin.js.br
- 5.5K - 17.plugin.js.gz
-  26K - 18.plugin.js
- 4.3K - 18.plugin.js.br
- 4.9K - 18.plugin.js.gz
-  58K - 19.plugin.js
-  14K - 19.plugin.js.br
-  16K - 19.plugin.js.gz
- 7.3K - 20.plugin.js
- 2.1K - 20.plugin.js.br
- 2.4K - 20.plugin.js.gz
- 3.5K - 21.plugin.js
- 1010 - 21.plugin.js.br
- 1.2K - 21.plugin.js.gz
- 5.5K - 22.plugin.js
- 1.4K - 22.plugin.js.br
- 1.6K - 22.plugin.js.gz
- 2.3K - 23.plugin.js
-  810 - 23.plugin.js.br
-  946 - 23.plugin.js.gz
- 2.8K - 24.plugin.js
-  897 - 24.plugin.js.br
- 1022 - 24.plugin.js.gz