[ASTERIXDB-2276][CONF] Introduce Max Active Writable Datasets - user model changes: no - storage format changes: no - interface changes: no
Details: - Introduce number of metadata datasets parameter and use it to reserve memory for all metadata datasets. - Default metadata dataset memory component number of pages to 32 pages. - Introduce max active writable datasets and use it to automatically calculate the number of pages of a user dataset memory component. - Remve the assumpation of reserving an NC core for heartbeats. - Fix for [ASTERIXDB-2279] by making the expected result order deterministic.