finished buy view

[awesominat]

this PR has the finalized version of the Buy View.

Salient Features:

1. Allows the user to input any ticker they want (case insensitive) and search for it. If the ticker does not exist, an error message informs the user of the "Incorrect ticker."
2. If searching is successful, a table gets populated with basic information on the stock, including the full name, website, current price, IPO, and others.
3. At the bottom, 3 new UI elements become visible: your current balance, an input field to enter how much of the stock you want to buy, and a purchase button.
4. When the user types any number in the input field (to say how much of the stock they want to buy) the balance text changes color between red and green to showcase ability to buy (accessibility issue)
5. The user can now see if they can buy said number of stock
6. Allows the user to buy the stock. If the purchase fails to go through (for example, insufficient balance), then an error message will pop up informing that they have no money.
7. If the purchase is successful, the screen updates the user's current balance and shows them a success popup saying that they purchase X number of Y stock.

Showcase:

[quiz3]

I read through all of the changes you have proposed. Most of them make sense to me, and for the other ones, I have confidence that you did the right thing for those. I look forward to using your TableModel to help complete the dashboard use case. I also look forward to learning from your references to help me complete the use case success view and output for the Get Company News use case.

Glad you were taking a look at my GetInfo use case. Not sure how useful it will turn out to be, but I think it could help to show some of the behind-the-scenes stuff going on in our app.