Expose _impl_writeable_tlv_based_enum_common macro

[tnull]

As it isn't currently, and it's used by the exposed impl_writeable_tlv_based_enum and impl_writeable_tlv_based_enum_upgradble.

[codecov-commenter]

Codecov Report

Patch coverage: 100.00% and project coverage change: -0.01 ⚠️

Comparison is base (36834b3) 91.13% compared to head (5af4076) 91.13%.

📣 This organization is not using Codecov’s GitHub App Integration. We recommend you install it so Codecov can continue to function properly for your repositories. Learn more

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2091      +/-   ##
==========================================
- Coverage   91.13%   91.13%   -0.01%     
==========================================
  Files         101      101              
  Lines       48887    48887              
  Branches    48887    48887              
==========================================
- Hits        44555    44554       -1     
- Misses       4332     4333       +1     

Impacted Files	Coverage Δ
lightning/src/util/ser_macros.rs	92.08% <100.00%> (ø)
lightning/src/ln/functional_tests.rs	98.19% <0.00%> (-0.05%)	⬇️
lightning/src/routing/router.rs	94.74% <0.00%> (+0.04%)	⬆️
lightning-invoice/src/payment.rs	81.73% <0.00%> (+0.96%)	⬆️

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.