Remove Page cache

[rymsha]

Page cache is a workaround for a bug enonic/xp#10800

[ComLock]

As a side note there are currently 6 caches in lib-react4xp:
https://github.com/search?q=repo%3Aenonic%2Flib-react4xp%20newCache(&type=code

[rymsha]

I guess we are talking about 3 here templateDescriptorCache.ts, contentTypeToPageComponentCache.ts, pageTemplateContentIdToPageComponentCache.ts

[rymsha]

enonic/xp#10800 fixed issue with unresolved page templates. all 3 caches are used in workarounds.
They are actually buggy:

• they break experience in development - as for 10 minutes changes they cache won't be seen
• templateDescriptorCache does not take into account that application of descriptor can be from a different app, but with the same name
• regions are not correctly realigned according to descriptors

[rymsha]

also enonic/xp#10116 - no need to check for null for fragments path