This differential introduces methods in CommCoreModule to get one time keys batch and prekey for notifications olm account. Additionally corresponding method for primary olm account is
refactored. The refactor gives us control on how many one time keys are generated (previously we were restricted to the default value in CryptoModule.h). Implemented and refactored methods return JS
objects of types `OLMOneTimeKeys` or `OLMPrekey` respectively. Note that `getUserOneTimeKeys` returned raw string previously.
This differential seems to be broad but only changes in `CommCoreModule.cpp` matter. The rest is boilerplate.