Add Integrity enforcement for all Persisted Data Files

[TanmoySG]

Currently all files are stored in FS as JSON and loaded from same. If someone changes the data in file it effects the integrity of the persisted data. To make sure we can identify if integrity has been compromise, we can

• Create a Integrity File
• Store SHAx of the data being persisted
• To ensure in-time/exact integrity check, use Timestamp involved integrity check,

{
    "hash" : "jhdfbvjofvo239u9023hfd2jb",
    "timestamp" : 1234567,
}

The above can be file.integrtity

• While loading from file, use the integrity file to check for integrity.
• While unloading to file, refresh the integrity file with timestamp and hash.