feat: support additional properties to utility method

This PR enhances the utility method to support additional properties. For instance, the lineClamp property does have additional properties but those can't be passed to the lineClamp(value) utility method.

Before

/** Sets `WebkitLineClamp: value`. */
  lineClamp(value: Properties["WebkitLineClamp"]) {
    return this.add("WebkitLineClamp", value);
  }

After

/** Sets `WebkitLineClamp: value`. */
  lineClamp(value: Properties["WebkitLineClamp"]) {
    return this.add("WebkitLineClamp", value) // default def
    .add("overflow", "hidden").add("display", "-webkit-box").add("WebkitBoxOrient","vertical",).add("textOverflow", "ellipsis"); // additional defs
  }

With these changes, lineClamp(value) will have the ability to define additional properties combining to the value param.

Also, added a few tests for packages/truss/src/methods.test.ts

cc @bdow since he's going to use it.

homebound-team / truss

feat: support additional properties to utility method #120