Expenses Billed to Others

[bradley-holt]

For expense fields (see #26 and #27), we need two additional fields:

1. "Travel Expenses Billed to Someone Else" (travel_expenses_other)
2. "Non-Travel Expenses Billed to Someone Else" (non_travel_expenses_other)

We also need to update the following labels (leaving the underlying field names as-is):

1. "Travel Expenses" → "Travel Expenses Billed to My Manager"
2. "Non-Travel Expenses" → "Non-Travel Expenses Billed to My Manager"

Notes:

• Please preserve the emphasis in the above wording.
• Please add the "Billed to Someone Else" fields after the "Billed to My Manager" fields.