Feature/email settings

[gondzo]

@vikasrohit Before deploying this one, you need to manually execute this script on the notifications database https://github.com/maxceem/tc-notifications/blob/5e1700ec7e294f22517e89445db2137485dd02ca/migrations/v2.0.sql

then just merge this PR and the one in connect-app repo. There are no new environment variables

appirio-tech/connect-app#2007

[vikasrohit]

Oky @gondzo. I didn't understood the usage of the name field, it is intialized with enabled which does seems to justify the field name.
Also, do we need to run any script to update existing data for rename of column deliveryMethod? or is it okay to keep existing values for this column?

[gondzo]

deliveryMethod values should be same as before (web/email)

name field is added for supporting generic value types in the future. Right now we only have a toggle (on/off) that is named enabled. If we later decide to add a new setting (targetEmail for example), we would still be able to use the same table structure.