ckb-debugger 0.20.0-rc4

Added three execution modes: full, fast and gdb

# full mode
# full mode is the default execution mode, and the usage of this mode as usual
$ ckb-debugger --tx-file=... --script-group-type=... --script-hash=...

# full mode support dummy tx
$ ckb-debugger --bin ...

# fast mode
# fast mode use asm machine to execute transactions, it lacks most of the debugging capabilities, such as pprof and heap/stack check
$ ckb-debugger --mode fast --tx-file=... --script-group-type=... --script-hash=...

# gdb mode
# gdb mode has no changes
$ ckb-debugger --mode gdb --gdb-listen ... ...