Add product_analytics_data_collector_host column to application_settings

What does this MR do and why?

This MR adds a new text type column called product_analytics_data_collector_host in the application_settings column. The column will be used to store the collector host. Currently, this value is set using jitsu_host.

The current MR only adds the text column. Several follow up MRs are planned as follows.

• Add a migration to add text limit
• Fill the collector_host for the projects where product analytics is enabled. Currently only internal projects have this field as the feature is not enabled globally.
• Add an application level validation on the presence of the column if product analytics is enabled
• Use the value from the newly added column in the ee/app/views/projects/product_analytics/dashboards.html.haml

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

How to set up and validate locally

1. Run migrations
2. You should see the new column in the application_settings table.

Notes:

1. with_lock_retries is not used since application_settings is not listed as a high traffic table
2. There was an unrelated diff in the structure.sql due to different ordering of some existing columns. I had to manually commit only changed line.
3. A follow up MR will add a text limit to the column.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #389490 (closed)