Added a CredentialManager to save our secrets

[parithon]

Added files

credentialManager.ts

I added a credentialManager.ts to set and retrieve the ClientId and Token from the users keychain (credential store). This uses a node module (keytar) but loads it using VSCode's version of Node.

Changed files

package.json

I added 4 commands:

• twitchhighlighter.setTwitchClientId
• twitchhighlighter.removeTwitchClientId
• twitchhighlighter.setTwitchPassword

• twitchhighlighter.removeTwitchPassword

  I removed the twitchhighlighter.password extension setting because the password will no longer be saved there

extension.ts

I setup the registration of the commands and created the handlers I changed the startChatHandler to first retrieve the TwitchCredentials from the CredentialManager before starting the client

server.ts

I declared the ttvChatClient within the connection.onInitialize function so we can initialize the twitchCredentials prior to retrieving the twitch chat options I changed the getTwitchChatOptions function to get the password and clientId from twitchCredentials