fix(grpc-message): show Add message for client-streaming/bidi-streaming methods.

[rajashreehj-bruno]

Jira: VSCODE-29/VSCODE-30

Description

Show Add Message for client-streaming / bidi-streaming methods. Add Message is hidden for other methods.

Problem

• Multiple messages are shown when it's not client-streaming / bidi-streaming methods.
• Unable to add multiple messages

Fix

• Add Message is available for client-streaming / bidi-streaming methods. Multiple messages can be added here.
• If it's not client-streaming / bidi-streaming methods, then multiple messages cannot be added and Add Message is hidden.
• When user switches client-streaming -> unary -> bidi-streaming - the messages added in client-streaming will be visible for bidi-streaming

Screenshot

Screen.Recording.2026-08-19.at.1.32.15.PM.mov