Add profiles

[Saakshaat]

A profile should represent a separate database with its own memory. The current codebase has the code to facilitate profiles but there are weird issues from Click for the command groups and we'll have to override some functions in parent class to resolve this.

After adding profiles, the user should be able to access different profiles for commands like this:

$ notes work add "Finish backend backlog"

$ notes work show
       Date         |         Content
--------------------|--------------------
11:39 ~ 28 Dec 2020 | Finish backend backlog

$ notes groceries add "Coconut milk"

$ notes groceries show
       Date         |         Content
--------------------|--------------------
11:40 ~ 28 Dec 2020 | Coconut milk

$ notes work show
       Date         |         Content
--------------------|--------------------
11:39 ~ 28 Dec 2020 | Finish backend backlog