prevent false featured snaps indicators

[ilayda-cp]

Done

/store?categories=featured&q=foo ==> featured
/store?page=3&categories=featured --> featured
/store --> featured
/store?page=2 --> featured
/store?page=2&q=ubuntu --> not featured
/store?page=2&categories=games --> not featured

How to QA

NA

Testing

• This PR has tests
• No testing required (explain why):

Security

• Security considerations for review (list them):
  • Examples:
  • Access control: users can only access their own data
  • Input: user input is validated and sanitised
  • Sensitive data: secret or private data is not exposed in any way
  • ...
• This PR has no security considerations (explain why):

Issue / Card

Fixes #

Screenshots

UX Approval

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• This PR does require UX approval (add context):

[webteam-app]

Demo

Jenkins

demos.haus

[steverydz]

LGTM 👍