Email/query Allow filtering by mailbox

[remk]

First ticket to implement the filtering when querying emails.
The handling of shared mailbox will be done later in another issues

Why

As an user i want to be able to select the mail in a mailbox like this :

[[ "Email/query",{
  "accountId": "ue150411c",
  "filter":  {
     "inMailbox": "myMailboxID"
}
}, "0" ]]

I also want to be able to select emails NOT in a set of mailboxes

[[ "Email/query",{
  "accountId": "ue150411c",
  "filter":  {
     "inMailboxOtherThan": ["myMailboxID1", ""myMailboxID2"]
}
}, "0" ]]

HOW

• accept a simple FilterCondition with an optional 'inMailbox' field
• accept a simple FilterCondition with an optional 'inMailboxOtherThan' field
• filter the query with the provided mailboxId

Still to groom

• error when mailbox not found or empty result ?

DOD

• write integration demonstrating that a user can filter the email of one of its mailbox.

• write integration demonstrating that a user can filter the email not in some of its mailboxes.

• write integration demonstrating that a user can filter the email by both those filters. The expected result is the intersection of the results of both filters.

[chibenwa]

error when mailbox not found or empty result ? => empty result. Error if the mailboxId is invalid...