Ease custom operation configuration

[antograssiot]

Q	A
Bug fix?	no
New feature?	yes
BC breaks?	no
Deprecations?	no
Tests pass?	yes
Fixed tickets
License	MIT
Doc PR	will open this is upvoted

Inspired by and following #1470 This PR aims to give a shortcut configuration for custom operation. Over the time I find my self repeating this code a lot.

Before:

/**
 * @ApiResource(
 *     collectionOperations={
 *         "get",
 *         "post",
 *         "custom_denormalization_action"={"route_name"="custom_denormalization_action"},
 *     },
 *     itemOperations={
 *         "get",
 *         "put",
 *         "custom_normalization_action"={"route_name"="custom_normalization_action"},
 *     }
 * )
 */

After:

/**
 * @ApiResource(
 *     collectionOperations={"get", "post", "custom_denormalization_action"},
 *     itemOperations={"get", "put", "custom_normalization_action"}
 * )
 */

[antograssiot]

I'll prepare a doc PR

[dunglas]

Thanks again Anto!