de319670ae feat: Create relative lock times at compile time (Christian Lewe)
53e1fb6b0c feat: Create absolute lock time at compile time (Christian Lewe)
Pull request description:
I noticed that I cannot create lock times as compile-time constants. This PR tries to remedy this issue by marking lock time constructors as `const`.
Because the `internals` crate depends on the `units` crate in a way that I don't fully understand yet, this PR updates the `units` crate only.
If `from_consensus` is being kept non-`const` by design, to keep the API flexible to future changes, then please close this PR. In this case, I overlooked existing discussions.
ACKs for top commit:
apoelstra:
ACK de319670ae successfully ran local tests; good start; should backport
tcharding:
ACK de319670ae
Tree-SHA512: 69f9147707bcf8f91f755dd6d1be5ed08945e775ee46918e33d77a9d07ce474047a80ed1226134a3914ead51d1ddbbc657552ca934dc3c079b92ad3d50b13152