d94d34f05f4ae3efa07de409489d68bbcc216346 doc: update developer notes wrt unix epoch time (Jon Atack)
e2f32cb5c5c7f2b1d1fc7003587b6573fb59526a qa: unify unix epoch time descriptions (Jon Atack)
Pull request description:
Closes #17613.
Updated call sites: mocktime, getblockheader, getblock, pruneblockchain,
getchaintxstats, getblocktemplate, setmocktime, getpeerinfo, setban,
getnodeaddresses, getrawtransaction, importmulti, listtransactions,
listsinceblock, gettransaction, getwalletinfo, getaddressinfo
Commands for testing manually:
```
bitcoind -help-debug | grep -A1 mocktime
bitcoin-cli help getblockheader
bitcoin-cli help getblock
bitcoin-cli help pruneblockchain
bitcoin-cli help getchaintxstats
bitcoin-cli help getblocktemplate
bitcoin-cli help setmocktime
bitcoin-cli help getpeerinfo
bitcoin-cli help setban
bitcoin-cli help getnodeaddresses
bitcoin-cli help getrawtransaction
bitcoin-cli help importmulti
bitcoin-cli help listtransactions
bitcoin-cli help listsinceblock
bitcoin-cli help gettransaction
bitcoin-cli help getwalletinfo
bitcoin-cli help getaddressinfo
```
---
Backport of Core PR17617
Note: used the newly introduced constant in two instances not covered in
the backport, specifically in getrawtransaction and getblocktemplate