Change default numeric precision_step

Change the default numeric precision_step to 16 for 64-bit types,
8 for 32-bit and 16-bit types. Disable precision_step for the 8-bit
byte type.

Closes #5905
Change default recovery throttling to 50MB / sec

The current setting of 20MB/sec seems to be too conservative given
the capabilities of modern hardware / network throughput.
A 50MB default should provide better out of the box performance.
Closes #5882
[TEST] Randomized number of replicas between 0 and the number of data nodes - 1 (rather than just between 0 and 1)

Closes #5896
Include name of the field that caused a circuit break in the log and exception message

Fixes #5718
Closes #5841