Implement post filter support

[armanmoztar]

Feature

Create endpoint to allow users filter the posts feed according to the user query (tags, post content, title, etc.)

Requirements

1. There must be a get API endpoint that fits all the filtering criteria in the request url, i.e. no body
2. The filtering must work on the relevant attributes of posts (tags, contain keyword, number of views, etc.)
3. The API should allow for sorting (most views on top)
4. The API should support pagination