[mathisarends]

Move the library's error definitions from cdpify.exceptions to cdpify.error so the module matches the public CDPError naming.

All internal and test imports now use the new module. Root-package error exports, the class hierarchy, and existing deprecated class aliases retain their behavior.

Breaking change: cdpify.exceptions is removed. Replace imports such as:

from cdpify.exceptions import CDPCommandError

with:

from cdpify.error import CDPCommandError

from cdpify import CDPCommandError continues to work. README and the Unreleased changelog document the migration.

Validation:

• 298 unit tests passed.
• Ruff lint and formatting passed; Pyright reported zero errors or warnings.
• Built a wheel from a fresh source copy and verified new-module imports and root-export identity, with the old module absent.