MAINT BREAKING: Rename PromptConverter to Converter

[jsong468]

Description

Renames the converter base class and module namespace ahead of the 1.0 release. PromptConverter becomes Converter and the pyrit.prompt_converter package becomes pyrit.converter, applied consistently across code, tests, and documentation. No backward-compatibility aliases are provided as this is a breaking change for 1.0.

Changes

• Base class: PromptConverter → Converter; file prompt_converter.py → converter.py.
• Package: pyrit/prompt_converter/ → pyrit/converter/ (moved via git mv, history preserved).
• Tests: tests/unit/prompt_converter/ → tests/unit/converter/.
• Config class: PromptConverterConfiguration → ConverterConfiguration.
• All references updated across imports, type hints, docstrings, and docs (.py / .ipynb pairs kept in sync).

Intentional exceptions (not renamed)

• MathPromptConverter / math_prompt_converter — "MathPrompt" is the attack technique name, not the base class.
• ImagePromptStyleConverter / image_prompt_style — unrelated identifier; does not contain the target token.

Tests and Documentation

• git grep confirms zero remaining PromptConverter / prompt_converter references in committable files (excluding the intentional exceptions above).
• Full package imports cleanly; pyrit.converter exposes Converter, ConverterResult, and all members.
• Unit tests pass across all affected areas: converters (1,031), prompt_normalizer (53), executor + scenario (1,767), and remaining suites (7,269)
• Notebook outputs are unchanged except doc/code/setup/1_configuration.ipynb, where one cached default_values line reflects the new class name (Converter.converter_target) — matching what a live re-run produces.
• Note that the above notebook cell in 1_configuration.ipynb may be outdated/broken due to removal of SimpleInitializer and requires follow up for fix.

[rlundeen2]

Approved with nits on stale doc strings and things

[rlundeen2]

Rich agrees with this comment but it is copilot generated: nit: one more cosmetic rename leftover I couldn't attach inline (GitHub sees converter.py as a rename so the line is unchanged context): pyrit/converter/converter.py line 96 — the __init__ docstring still says "Initialize the prompt converter." and should be "Initialize the converter." to match the rename.