[Enhancement]: Provide `$top` as a synonym for `$first` in REST

[JerryNixon]

Proposal

Provide $top as a synonym for $first in REST with no other behavioral change.

Reasons for this minor change:

Alignment with data source syntax is only a coincidence. Intuitive use and OData alignment are the primary drivers.

Database	Keyword Used	Example Syntax
Cosmos DB	TOP	SELECT TOP 5 Id, Name FROM Users
SQL Server	TOP	SELECT TOP 5 Id, Name FROM Users
MySQL	LIMIT	SELECT Id, Name FROM Users LIMIT 5
PostgreSQL	LIMIT	SELECT Id, Name FROM Users LIMIT 5

Why is this proposal specific to REST?

In GraphQL, first is more common than top. first is typically used in pagination, particularly with Relay-style connections. It specifies the number of items to retrieve starting from the current cursor. top is not standard in GraphQL queries. If you encounter it, it’s likely specific to a custom schema.

query {
  users(first: 5) {
    edges {
      node {
        id
        name
      }
    }
  }
}

Current behavior

URL	QUERY
https://server/api/User? $select=Id,Name	SELECT Id, Name FROM User
&$first=10	SELECT TOP 10 Id, Name FROM User

Proposed behavior

URL	QUERY
https://server/api/User? $select=Id,Name	SELECT Id, Name FROM User
&$first=10	SELECT TOP 10 Id, Name FROM User
&$top=10	SELECT TOP 10 Id, Name FROM User

// end

[JerryNixon]

Related #2344