perf(dapi): use cached core height in streaming endpoints

[shumkov]

Issue being fixed or feature implemented

In order to reduce amount of Core RPC calls (which is slow), we should use already available chain height.

What was done?

• Use height from ChainDataProvider instead of calling getBestBlockHeight every request in subscribeToTransactionsWithProofs and subscribeToBlockHeadersWithChainLocks

How Has This Been Tested?

Updated tests

Breaking Changes

None

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional/e2e tests
• I have added "!" to the title and described breaking changes in the corresponding section if my code contains any
• I have made corresponding changes to the documentation if needed

For repository code-owners and collaborators only

• I have assigned this pull request to a milestone