Enhance plugin-hash to allow callers to optionally pass values for size, smallerSize in ImagePHash

**Is your feature request related to a problem? Please describe.**
The pHash functionality from plugin-hash althought allows control on specificity of uniqueness of pHash with size and smallerSize in constructor of ImagePHash, the exported methods like `pHash` call the ImagePHash without any constructor argument forwarded from client.

**Describe the solution you'd like**
Add optional params to exported method signatures like `pHash(image: I, options?: {size?: number, smallerSize?: number})`