feat: Ability to align all columns with a single Alignment

[DenverCoder1]

A single alignment type can be used for all columns::

table2ascii(
    header=["First Name", "Last Name", "Age"],
    body=[
        ["John", "Smith", 30],
        ["Jane", "Doe", 28],
    ],
    # Align all columns to the left
    alignments=Alignment.LEFT,
)

╔══════════════════════════════╗
║ First Name   Last Name   Age ║
╟──────────────────────────────╢
║ John         Smith       30  ║
║ Jane         Doe         28  ║
╚══════════════════════════════╝