Adds an opt-in McpClient builder option `applyElicitationDefaults(boolean)`
that, when enabled, fills missing keys of an accepted ElicitResult.content
with `default` values declared in the requestedSchema before returning the
result to the server. Mirrors the TypeScript SDK's applyElicitationDefaults
behavior, but exposed as a local client config rather than a wire capability.
Co-authored-by: Sainath Reddy Bobbala <bsnr@amazon.com>
Signed-off-by: Dariusz Jędrzejczyk <2554306+chemicL@users.noreply.github.com>