feat: Add balance attribute to account.

[bvanelli]

Includes the property for balance on the accounts object. Here is the result:

The result of the property:

from actual import Actual
from actual.queries import get_accounts


with Actual("http://localhost:5006", password="mypass", file="My Finances") as actual:
    accounts = get_accounts(actual.session)
    for acct in accounts:
        print(f"Balance for {acct.name} is {acct.balance}")

The output from the script:

Balance for SimpleFIN Savings is 115524.49
Balance for SimpleFIN Checking is 26134.41

Closes #21

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.16%. Comparing base (2bcc2cb) to head (fd2a1b4).

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #23      +/-   ##
==========================================
+ Coverage   94.75%   96.16%   +1.40%     
==========================================
  Files           9        9              
  Lines        1412     1434      +22     
==========================================
+ Hits         1338     1379      +41     
+ Misses         74       55      -19     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.