[Refactor] Refactoring services to use interfaces

[samuelIkoli]

Description

Refactoring of services to use interfaces.

Acceptance Criteria

• All services worked on should retain their logic and functionality
• All services worked on should be interfaced correctly

Purpose

• To improve code modularity, testability, and adherence to the dependency inversion principle.

Requirements

Will be divided into 3 to be worked on by 3 contributors

1. actions, auth, billing, category, jobpost, key, ping, superadmin, templates - @samuelIkoli
2. notificationCRUD, product, profile, seed, send, squeeze, testimonial, user, waitlist - @Jidetireni
3. blog, contact, faq, helpcenter, image, invite, newsletter, notification, organisation - @BerylCAtieno

Expected Outcome

• Every service works as it was working before without any change at all in logic or behaviour.

[BerylCAtieno]

I will be working on this with you

[Jidetireni]

I will also being making contributions to this issues.

[omotomiwa26]

@samuelIkoli @BerylCAtieno @Jidetireni , kindly add your slackIDs in the issues's comments

[Jidetireni]

Tireni

[samuelIkoli]

My Slack ID - Sabi Boy

[BerylCAtieno]

My Slack ID - BerylBCA