Honor types in rippled feature command (Version: [1.12.0])

[pkcs8]

Issue Description

Until rippled-1.11.0 rippled feature command used to print a list of amendments along with the following properties:

 "93E516234E35E08CA689FA33A6D38E103881F8DCB53023F728C307AA89D515A7" : {
    "count" : 12,
    "enabled" : false,
    "name" : "XRPFees",
    "supported" : true,
    "threshold" : 28,
    "validations" : 35,
    "vetoed" : true
 },

However, since rippled-1.12.0, it marks obsolete amendments as:

 "86E83A7D2ECE3AD5FA87AB2195AE015C950469ABF0B72EAACED318F74886AE90" : {
    "count" : 0,
    "enabled" : false,
    "name" : "CryptoConditionsSuite",
    "supported" : true,
    "threshold" : 28,
    "validations" : 35,
    "vetoed" : "Obsolete"          // type error
 },

The property vetoed is boolean, therefore assigning it a value of Obsolete would break (or require special handling) in type safe languages. Its not a lot of data, so a new optional property named obsolete may be introduced, which can simply say "obsolete": true.

Steps to Reproduce

rippled feature

Expected Result

It would be great if rippled honored types so that its easy to parse the JSON without special handling.

 "86E83A7D2ECE3AD5FA87AB2195AE015C950469ABF0B72EAACED318F74886AE90" : {
    "count" : 0,
    "enabled" : false,
    "name" : "CryptoConditionsSuite",
    "supported" : true,
    "threshold" : 28,
    "validations" : 35,
    "vetoed" : true,
    "obsolete": true          // new property
 },

Actual Result

 "86E83A7D2ECE3AD5FA87AB2195AE015C950469ABF0B72EAACED318F74886AE90" : {
    "count" : 0,
    "enabled" : false,
    "name" : "CryptoConditionsSuite",
    "supported" : true,
    "threshold" : 28,
    "validations" : 35,
    "vetoed" : "Obsolete"          // type error
 },

Environment

rippled version 1.12.0