Add json_schema column to candidate config

[manuranga]

Following table structure is expected

CREATE TABLE `CANDIDATE_CONFIG` (
  `ID` varchar(36) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL,
  `KEY_NAME` varchar(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci DEFAULT NULL,
  `DESCRIPTION` varchar(100) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci DEFAULT NULL,
  `JSON_SCHEMA` varchar(255) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
  PRIMARY KEY (`ID`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

INSERT INTO `` (`ID`,`KEY_NAME`,`DESCRIPTION`,`JSON_SCHEMA`) VALUES ('1','FULL_NAME','Name Of Candidate (Full Name)','');
INSERT INTO `` (`ID`,`KEY_NAME`,`DESCRIPTION`,`JSON_SCHEMA`) VALUES ('2','PREFERRED_NAME','Preferred Name',NULL);
INSERT INTO `` (`ID`,`KEY_NAME`,`DESCRIPTION`,`JSON_SCHEMA`) VALUES ('3','NIC','National Identity Card (NIC)',NULL);
INSERT INTO `` (`ID`,`KEY_NAME`,`DESCRIPTION`,`JSON_SCHEMA`) VALUES ('4','DATE_OF_BIRTH','Date of Birth','{\"type\":\"string\",\"format\":\"date\"}');
INSERT INTO `` (`ID`,`KEY_NAME`,`DESCRIPTION`,`JSON_SCHEMA`) VALUES ('5','GENDER','Gender','{\"oneOf\":[{\"type\":\"string\",\"enum\":[\"MALE\"],\"title\":\"Male\"},{\"type\":\"string\",\"enum\":[\"FEMALE\"],\"title\":\"Female\"}],\"type\":\"string\"}');
INSERT INTO `` (`ID`,`KEY_NAME`,`DESCRIPTION`,`JSON_SCHEMA`) VALUES ('6','ADDRESS','Address',NULL);
INSERT INTO `` (`ID`,`KEY_NAME`,`DESCRIPTION`,`JSON_SCHEMA`) VALUES ('7','OCCUPATION','Occupation',NULL);