ENV vars for OPENSSL_NO_ASM

[justsmth]

Issues:

• Provides workaround for Build failed at target: aarch64-pc-windows-msvc #376 (or for other platforms where AWS-LC assembly fails to build)

Description of changes:

• AWS-LC contains optimized assembly language implementations for many primitive cryptographic operations. As a fall-back, these operations also have a C-implementation provided.
• For most platforms, CMake correctly detects whether/which assembly files should be built. However, CMake's detection is sometimes inadequate or the build environment lacks an assembler (such as NASM), and the OPENSSL_NO_ASM flag must be passed to avoid build failures.
• The OPENSSL_NO_ASM flag may also be useful for debugging failing cryptographic operations.

Call-outs:

• The C-implementations are significantly slower than their assembly-language counterparts.
• The OPENSSL_NO_ASM flag is only allowed for un-optimized/debug builds.

Testing:

• Updated CI.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license and the ISC license.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.82%. Comparing base (972db16) to head (2d7fdb0).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #377   +/-   ##
=======================================
  Coverage   95.82%   95.82%           
=======================================
  Files          60       60           
  Lines        7865     7865           
=======================================
  Hits         7537     7537           
  Misses        328      328           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.