Add settings to turn on off features and fix JSONB error for admin page

[Jonathanlau92]

Description

1. Add settings to turn on/off features of Overture

• Add jSON settings to check if feature is turn on or off (true or false)
• Features includes: search_feature, kanban_board, dataroom, our_investor_or_startup, cap_table, performance_report, shared_file, resource_portal

2. Fix JSONB error in administrate

• Previously, saving JSON array turns the value in string. Added a model method to write/parse the value into JSON before saving into the database. This solution is a temporary workaround given by the gem owner, found in this issue: save field results in to_s version all the time codica2/administrate-field-jsonb#1
• This workaround suffices while waiting for the gem owner to fix it
• Added display for the JSON (mainly the settings and the products) - can finally add products through the admin page

Notion link: https://www.notion.so/Setting-to-turn-on-off-features-in-Overture-5f22cc7cf45c4b4bbd92295d9f820160

Remarks

• NIL

Testing

• Tested by turning on-off overture feature for a startup account
• Tested that can edit json value in admin page
• Run through every page of overture to see if its still working fine