feat: show which mutual fundes use the stock

[shivamsouravjha]

• Since we've collection of stocks and mutual funds, let's have a section in stocks where we can see which mutual funds invest in this stock so that user can find how many mutual fund in our collections are investing in this stock.
• we should have a count of total available mutual funds too so that user know how many unique mutual funds we have( can be retireved from the parse xlsx file)