ORC-1509: Auto grant contributor role to first-time contributors

### What changes were proposed in this pull request?

This PR aims to grant 'Apache ORC Contributor' role to the first-time contributors.

### Why are the changes needed?

To provide more convenient ways to the Apache ORC committers

### How was this patch tested?

Manual.

Closes #1621 from dongjoon-hyun/ORC-1509.

Authored-by: Dongjoon Hyun <dongjoon@apache.org>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>

dev/merge_orc_pr.py

@@ -373,7 +373,22 @@ def choose_jira_assignee(issue, asf_jira):
                 except BaseException:
                     # assume it's a user id, and try to assign (might fail, we just prompt again)
                     assignee = asf_jira.user(raw_assignee)
-                asf_jira.assign_issue(issue.key, assignee.name)
+                try:
+                    assign_issue(asf_jira, issue.key, assignee.name)
+                except Exception as e:
+                    if (
+                        e.__class__.__name__ == "JIRAError"
+                        and ("'%s' cannot be assigned" % assignee.name)
+                        in getattr(e, "response").text
+                    ):
+                        continue_maybe(
+                            "User '%s' cannot be assigned, add to contributors role and try again?"
+                            % assignee.name
+                        )
+                        grant_contributor_role(assignee.name, asf_jira)
+                        assign_issue(asf_jira, issue.key, assignee.name)
+                    else:
+                        raise e
                 return assignee
         except KeyboardInterrupt:
             raise
@@ -382,6 +397,25 @@ def choose_jira_assignee(issue, asf_jira):
             print("Error assigning JIRA, try again (or leave blank and fix manually)")
 
 
+def grant_contributor_role(user: str, asf_jira):
+    role = asf_jira.project_role("ORC", 10010)
+    role.add_user(user)
+    print("Successfully added user '%s' to contributors role" % user)
+
+
+def assign_issue(client: jira.client.JIRA, issue: int, assignee: str) -> bool:
+    """
+    Assign an issue to a user, which is a shorthand for jira.client.JIRA.assign_issue.
+    The original one has an issue that it will search users again and only choose the assignee
+    from 20 candidates. If it's unmatched, it picks the head blindly. In our case, the assignee
+    is already resolved.
+    """
+    url = getattr(client, "_get_latest_url")(f"issue/{issue}/assignee")
+    payload = {"name": assignee}
+    getattr(client, "_session").put(url, data=json.dumps(payload))
+    return True
+
+
 def resolve_jira_issues(title, merge_branches, comment):
     jira_ids = re.findall("ORC-[0-9]{4,5}", title)