This is a backport of Core PR14918
In order to automate somewhat the process, I used the following commands:
sed -n '1h; 1!H; ${ g; s@/\* opt \*/ true,\n \+@/* opt */ true, @g; p}' -i ../src/wallet/rpc*.cpp ../src/rpc/*.cpp
sed -n '1h; 1!H; ${ g; s@/\* opt \*/ false,\n \+@/* opt */ false, @g; p}' -i ../src/wallet/rpc*.cpp ../src/rpc/*.cpp
sed -e 's@/\* opt \*/ false, /\* default_val \*/ ""@RPCArg::Optional::NO@' -i ../src/wallet/rpc*.cpp ../src/rpc/*.cpp
# Manual edit for OMITTED and OMITTED_NAMED_ARG
sed -e 's@/\* opt \*/ true, /\* default_val \*/@/* default */@' -i ../src/wallet/rpc*.cpp ../src/rpc/*.cpp