Merge bitcoin/bitcoin#23636: Remove GetAdjustedTime from init.cpp

fa551b3bdd Remove GetAdjustedTime from init.cpp (MarcoFalke)
fa815f8473 Replace addrman.h include with forward decl in net.h (MarcoFalke)

Pull request description:

  It seems confusing to call `GetAdjustedTime` there, because no offset could have been retrieved from the network at this point. Even if connman was started, `timedata` needs at least 5 peer connections to calculate an offset.

  Fix the confusion by replacing `GetAdjustedTime` with `GetTime`, which does not change behavior.

  Also:
  * Replace magic number with `MAX_FUTURE_BLOCK_TIME` to clarify the context
  * Add test, which passes both on current master and this pull request
  * An unrelated refactoring commit, happy to drop

ACKs for top commit:
  dongcarl:
    Code Review ACK fa551b3bdd, noticed the exact same thing here: https://github.com/bitcoin/bitcoin/pull/23280/commits/e073634c37f3a1e140920c6e5e3f2c1ae47cd293
  mzumsande:
    Code Review ACK fa551b3bdd
  jnewbery:
    Code review ACK fa551b3bdd
  shaavan:
    ACK fa551b3bdd
  theStack:
    Code-review ACK fa551b3bdd

Tree-SHA512: 15807a0e943e3e8d8c5250c8f6d7b56afb26002b1e290bf93636a2c747f27e78f01f1de04ce1a83d6339e27284c69c43e077a8467545c4078746f4c1ecb1164d

test/functional/test_framework/blocktools.py

@@ -50,6 +50,8 @@ MAX_BLOCK_SIGOPS_WEIGHT = MAX_BLOCK_SIGOPS * WITNESS_SCALE_FACTOR
 # Genesis block time (regtest)
 TIME_GENESIS_BLOCK = 1296688602
 
+MAX_FUTURE_BLOCK_TIME = 2 * 60 * 60
+
 # Coinbase transaction outputs can only be spent after this number of new blocks (network rule)
 COINBASE_MATURITY = 100