Changes related to creation of a modular backend in multiprecision [SyncWith: crypto3-multiprecision#70] #281

All 75 tests pass in 27s

16 files +12 16 suites +12 27s ⏱️ +27s
75 tests +70 75 ✔️ +70 0 💤 ±0 0 ❌ ±0
85 runs +75 85 ✔️ +75 0 💤 ±0 0 ❌ ±0

Results for commit 28f1ca2. ± Comparison against earlier commit bad7aa5.