Replace the resourceStorage implementation

[sameo]

Description of problem

The resourceStorage implementation is a wide spread dependency and prevents several key components (e.g. hypervisors) to be moved into their own package.

Expected result

Create a new store package that provides a storage implementation for virtcontainers, with the following features:

• Simplicity: The API should be short and simple.
• Transparency: The core virtcontainers code should not care about
  the storage backend details.
• Extensibility: It should be easily extensible to add non local and in
  memory backends.

[jodh-intel]

Related to the following PRs:

• persist: baseline persist data format #883
• [WIP][RFC]persist: baseline persist data format #874