stats: delayed start of initialization of some charts

[bragov4ik]

Is your feature request related to a problem? Please describe.
It's not a pleasant user and deploy experience to delay the whole service from launching when some charts can be updated correctly.

Describe the solution you'd like
Dynamic system to delay only parts of functionality when certain conditions are not met.

Describe alternatives you've considered
Disabling the corresponding stuff manually - too tedious.

Additional context
For now the most frequent part that is blocking service is internal txns indexing.

[bragov4ik]

also start some charts immediately (for main page)

[bragov4ik]

also this can be started on a separate condition of user ops being available #1112