feat: UI ComboBox component

[bmingles]

ui.combo_box

Testing

from deephaven import ui

@ui.component
def ui_combo_box():
    value, set_value = ui.use_state("")

    combo = ui.combo_box(
        "Text 1",
        "Text 2",
        "Text 3",
        label="Text",
        on_selection_change=set_value,
        selected_key=value,
    )

    text = ui.text("Selection: " + str(value))

    return combo, text

my_combo_box = ui_combo_box()

import deephaven.ui as ui
from deephaven import time_table
import datetime

# Ticking table with initial row count of 200 that adds a row every second
initial_row_count = 200
_table = time_table(
    "PT1S",
    start_time=datetime.datetime.now() - datetime.timedelta(seconds=initial_row_count),
).update(
    [
        "Id=new Integer(i)",
        "Display=new String(`Display `+i)",
    ]
)

@ui.component
def ui_combo_box_item_table_source(table):
    value, set_value = ui.use_state("")

    combo = ui.combo_box(
        ui.item_table_source(table, key_column="Id", label_column="Display"),
        label="Text",
        on_change=set_value,
        selected_key=value,
    )

    text = ui.text(f"Selection: {value}")

    return combo, text

my_combo_box_item_table_source = ui_combo_box_item_table_source(_table)

resolves #201