Changes after adding symbol actors

[Oriol Brufau]

In bug 1424722 I plan to add a symbol actor to symbol grips. Then,

• The symbol stubs should be updated.

  https://github.com/devtools-html/devtools-core/blob/94aae83569c2d27432008775bef7795ef66fe550/packages/devtools-reps/src/reps/stubs/symbol.js#L6-L13

  Something like actor: "server1.conn1.child1/symbol" + someNumber,

• A data-link-actor-id should be added in SymbolRep

  https://github.com/devtools-html/devtools-core/blob/94aae83569c2d27432008775bef7795ef66fe550/packages/devtools-reps/src/reps/symbol.js#L30

    return span({
      className,
      "data-link-actor-id": object.actor,
    }, `Symbol(${name || ""})`);

• Test that with expectActorAttribute

  https://github.com/devtools-html/devtools-core/blob/94aae83569c2d27432008775bef7795ef66fe550/packages/devtools-reps/src/reps/tests/symbol.js#L18

  const {
    expectActorAttribute
  } = require("./test-helpers");
  expectActorAttribute(renderedComponent, stub.actor);

[Oriol Brufau]

Fixed in #879