Feat: decode base64 hashFields to hexadecimal

[itsCheithanya]

Now the hash fields are in base64 encoded format which is hard for user readability instead make it hexadecimal which aligns with sha256sum cli format

  "ClusterName": "default",
  "Cwd": "/var/snap/snapd-desktop-integration/253/",
  "Data": "lsm=bprm_check_security",
  "ExecEvent": {
    "ExecID": "0",
    "ExecutableName": "snap-exec"
  },
  "HashAlgo": "sha256",
  "HostName": "cheithanya-lenovo-v14-ikb",
  "HostPID": 156140,
  "HostPPID": 1093,
  "NodeID": "33bac96b5b108c7ea6769a55d4fb2fdb6677d16701641d4b9fbda7841f38ad42",
  "Operation": "Process",
  "PID": 156140,
  "PPID": 1093,
  "ParentHash": "0000000000000000000000000000000000000000000000000000000000000000",
  "ParentProcessName": "/usr/lib/systemd/systemd",
  "ProcessHash": "bdf7e2223ca5b994d6c099382e76c64e3fd1d0eabb5d2e42fe2b6e771d550f9f",
  "ProcessName": "/usr/bin/bash",
  "Resource": "/snap/snapd-desktop-integration/253/snap/command-chain/desktop-launch",
  "ResourceHash": "0000000000000000000000000000000000000000000000000000000000000000",
  "Result": "Passed",
  "Source": "/snap/snapd-desktop-integration/253/snap/command-chain/desktop-launch /snap/snapd-desktop-integration/253/usr/bin/snapd-desktop-integration",
  "Timestamp": 1756998473,
  "Type": "SystemEvent",
  "UID": 1000,
  "UpdatedTime": "2025-09-04T15:07:53.038036Z"
}