Q/codewhisperer does not declare its position encoding

[justinmk3]

Problem

It seems like codewhisperer server expects utf-8 encoding,

language-servers/server/aws-lsp-codewhisperer/src/language-server/chat/contexts/utils.test.ts

Line 13 in 1c38b0c

const data = await fs.readFile(file, { encoding: 'utf8' });

but the default LSP encoding is utf-16.

Expected behavior

• Document the expected position encoding in the readme
• Declare the expected position encoding from the server settings/capabilities, so that clients don't have to guess it.
• (Optional) Declare utf-8 as the encoding expected by all the lsp servers in this repo? Mention this in the top-level docs, wherever those are...