Secret Keeper Application

[chenchanglew]

What this PR does / why we need it:

Create a new demo application ~ Secret Keeper

Secret Keeper has 5 functions.
InitSecretKeeper:

• This function will initialize the key "AUTH_LIST_KEY" with value ["Alice", "Bob"] and key "SECRET_KEY" with value "DefaultSecret".
• This function should only be called once when the application started.
• Of course a malicious user can call this function to reset the value, but this we will assume this is not what an attacker would want to achieve. RevealSecret:
• This function allow users that in the Authlist ("AUTH_LIST_KEY") able to reveal the value of secret stored under key "SECRET_KEY". LockSecret:
• This function allow users that in the Authlist ("AUTH_LIST_KEY") able to store a new value of secret under key "SECRET_KEY".
• The old value will be replaced. AddUser:
• This function allow users that in the Authlist ("AUTH_LIST_KEY") able to add a new user to the Authlist.
• Then the new user can now perform the following four functions (RevealSecret, LockSecret, AddUser, RemoveUser) RemoveUser:
• This function allow users that in the Authlist ("AUTH_LIST_KEY") able to add remove an existing user off the Authlist.
• Then the removed user can no longer able to perform the following four functions (RevealSecret, LockSecret, AddUser, RemoveUser)

Example using fpc-simple-client:
./fpcclient invoke initSecretKeeper
./fpcclient query revealSecret Alice
./fpcclient invoke lockSecret Bob NewSecret
./fpcclient query revealSecret Alice
./fpcclient invoke removeUser Alice Bob
./fpcclient query revealSecret Alice
./fpcclient query revealSecret Bob // (will failed) ./fpcclient invoke addUser Alice Bob
./fpcclient query revealSecret Bob // (will success)

Which issue(s) this PR fixes:

This is just create a new application for ppc example

Special notes for your reviewer:

[mbrandenburger]

@chenchanglew Can you please rebase your PR as we merged the fix for the broken GH actions

[mbrandenburger]

What about adding a readme file in the chaincode secret-keeper folder with a description on what it does and how to use it.

[mbrandenburger]

Thanks @chenchanglew, the added README looks good to me.

@munapower could you please check this PR? Thanks

[munapower]

Minor changes to readme to make it easier to follow.

[chenchanglew]

All the comments has been resolved