Add allowedMethods in the config on bootstrap and fix dataPath

[!shan]

Description

• When we bootstrap an application using lisk init command, currently by default it doesn't have allowedMethods in the rpc configuration. We can add allowedMethods: [] to config on bootstrap
• Also dataPath in config file is currently absolute path which can be replaced with homedir->~. Ex, dataPath : "~/.lisk/test-app"

Which version(s) does this affect? (Environment, OS, etc...)

v6.0.0