Interpolating Out[] puts an object, not text, into a text prompt

[JasonWeill]

Description

Interpolating the special Out[] array into a text prompt causes an object to be inserted into the prompt:

Out[9] should contain only the text A new moon has no illuminated portion visible, while a full moon has its entire disk fully illuminated by the sun. Instead, it is a TextWithMetadata object, not serialized as text when I interpolate it in In[10], so what gets translated into Spanish is a Python descriptor of an object.

One can work around this by calling .text on the Out[n] object:

%%ai chatgpt
Translate this sentence into Spanish: {Out[12].text}

Reproduce

1. Run an %%ai command with -f text specified as an option. The output appears as Out[9] in the above example.
2. Run another %%ai command with {Out[9]} as part of the prompt.
3. The prompt is interpreted to have jupyter_ai_magics.magics.TextWithMetadata, not str, as the type of Out[9].

Expected behavior

When interpolating a TextWithMetadata object, like Out[n], into a text prompt, the text portion should be used.

Context

• JupyterLab version: 3.5.3, with Jupyter AI 0.8.0

[JasonWeill]

The treatment of text as TextWithMetadata, not a TextDisplayObject, was introduced in #69 by @ellisonbg.