feat(api): add external API endpoint for updating urls

[halfwhole]

Problem

We want to add an external API endpoint for updating URLs (PATCH /api/v1/urls)

Solution

Added the updateUrl method to ApiV1Controller for updating URLs

Note that the request format is different for the internal vs. external APIs:

• Internal API: PATCH /api/v1/url, body must contain shortUrl
• External API: PATCH /api/v1/urls/:shortUrl

Possible future improvements:

• (For both internal and external APIs) Long URL Joi validation should also check for validity and circular redirects! Currently it only checks for HTTPS and blacklists, so invalid URLs + circular redirects only fails with Sequelize at the repo layer

Tests

• Unit tests for updating URLs

Should add integration tests, when we have them