[build] support mbedtls 3.x

[wgtdkp]

This PR adds support for building with mbedtls 3.x. Specifically:

1. some mbedtls APIs are removed or renamed in 3.x so that we need to do the migration
2. fix some fmtlib compile issues, e.g. making enums formattable
3. we changed to use MBEDTLS_CONFIG_FILE to specify the full configuration instead of leveraging MBEDTLS_USER_CONFIG_FILE on top of the default mbedtls configuration (this is for working around internal building issues)

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 33.84615% with 43 lines in your changes are missing coverage. Please review.

Project coverage is 72.98%. Comparing base (f63ec73) to head (7fa9518).

❗ Current head 7fa9518 differs from pull request most recent head ac19086. Consider uploading reports for the commit ac19086 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #249      +/-   ##
==========================================
- Coverage   73.33%   72.98%   -0.35%     
==========================================
  Files          71       71              
  Lines        7421     7477      +56     
==========================================
+ Hits         5442     5457      +15     
- Misses       1979     2020      +41     

Files	Coverage Δ
include/commissioner/error.hpp	100.00% <100.00%> (ø)
src/library/coap.hpp	96.38% <ø> (ø)
src/library/dtls.cpp	82.35% <100.00%> (+0.28%)	⬆️
src/library/dtls.hpp	100.00% <100.00%> (ø)
src/library/openthread/sha256.cpp	100.00% <ø> (ø)
src/library/coap.cpp	60.46% <25.86%> (-3.24%)	⬇️

[librasungirl]

👍