Changes related to creation of a modular backend in multiprecision [SyncWith: crypto3-multiprecision#70] #62

All 115 tests pass, 4 skipped in 5s

  36 files +  32   36 suites +32 5s ⏱️ +5s
119 tests +111 115 ✔️ +115   4 💤 +  4 0 ❌ -   8
576 runs +544 560 ✔️ +560 16 💤 +16 0 ❌ - 32

Results for commit b43075c. ± Comparison against earlier commit 841fde3.