Improve SPA caching

[pmoleri]

Why:
SPA had a 1 year cache for all static files, including the index.html

This is terribly bad for updating the app because you get an older version of the app unless you force reload.
This can also lead to crashes, because the cached index.html will reference related scripts that are no longer there.

e.g.

How:

• New rules:
  • index.html 5 min public cache
  • Hashed files 1 year immutable public cache
    • main-<hash>.js
    • chunk-<hash>.js
    • polyfills-<hash>.js
    • styles-<hash>.css

• Other static assets 1 hour

e.g.

Additionally:

• Enable SVG compression

This should apply to:

• angular-demos/
• angular-demos-grid-crm/
• angular-demos-lob/

After testing this, the same approach should be applied to:

• igniteui-angular-examples (angular-demos-dv/)
• angular-grid-examples

[turbobobbytraykov]

LGTM, let's give it a go