fix transaction_tests by using a ChainTestingSetup in the test that needs consensus params

add an Assert(node.chainman) to ensure the chainman is not nullptr, as the ChronikBridge code heavily depends on that.
Note that in the current state of the codebase this is already done in init.cpp before calling chronik::Start(config, node, fReindexChronik), but it doesn't hurt to check again for all case where ChronikBridge is instantiated directly (unit tests)

fix accidental :wq, convert a gArgs into args

fix doxygen comment for lock_points (remove duplicated part of a sentence from the coins_view doxygen comment from the previous function)

make chainparams const in fuzzer, add bitcoin-fuzzers to test plan

remove unneeded max_input_height computation in CalculateLockPointsAtTip

i think i need to remove some unused code

use tx.GetId()

better variable name

nit: make file permission and shebang conistent with other functional tests