feat(service): add ability to filter jobs by type

[jsam]

Currently, /jobs endpoint only supports listing all jobs for a user requesting the information. This could be overwhelming once we add different job types. For such cases, it would be helpful that we add a parameter type with which we can specify retrieval of only jobs with a given type.

Example:

GET /jobs?type=migrations
[
 { 
    "type": "migration",
    ....
 },
 {
    "type": "migration",
    ....
 }
]