Added transactions table and forms for adding manual transactions
   calpoly/api/api_misc.py: Added `/budget/` route to get transactions by category
   calpoly/frontend/static/css/consoles/budget.css: Styles for nested table in transactions table
   calpoly/frontend/static/css/consoles/finance.css: Removed filter select styling
   calpoly/frontend/static/css/pages/users_profile.css: Moved filter select styling here
   calpoly/frontend/static/js/consoles/budget.js: Code to fill out transaction table
   calpoly/frontend/static/templates/consoles/budget.html: Structure for transaction table and new forms