Add option for sending emails to new participants only

[Jcen902]

PR for #35 ,Add option for sending emails to new participants only, the change are:

1. Add a new button in study-detail page(and the associate .html and .ts).
2. A new table is create to store the list of email address that the study have sent invitation email to.
3. Study class have a new Set for saving the list of email address that the study have sent invitation email to. This Set is mapped by @ElementCollection into the table in 2.
4. StudyServce class's sendInvitationEmail() take the necessary information from study only instead of receiving the whole Study object.
5. StudyResource has two @put resource to handle send emails to all participants and send emails to new participants instead of just one.
6. A new @put for updating the list of email address that the study have sent to and for updating the table I mention in 2.
7. In study-component page, the "Send Invitation" button is link to the "View" button, which is, they are doing the same thing now as "Send Invitation" should provide the options for sending to all participants or to new participants only.

[Jcen902]

@nateeo @jsoulsby Here you are, just base on my old code with some small fix

[nateeo]

LGTM 👍

[jsoulsby]

Looking good overall, nice work on the modal 👍

[jsoulsby]

Shouldn't this be "send the study to all participants"?

[Jcen902]

@jsoulsby Fixed

[Jcen902]

@softeng-701 Merge please.

[Jcen902]

@softeng-701 Squash is done. @nateeo there because he teach me about squashing