fix: formatting via lsp is broken for another buffer

[mityu]

Problem
When execute lsp format for another buffer, wrong and unexpected textEdit changes may will happen because internal lsp format request is issued with using the current buffer contents.

Reproduce steps

• Prepare empty a.ts.
• Prepare this b.ts

function _f(_loooooooooooooongFirstArgument: number, _looooooooooooooongSecondArgument: number, _looooooooooooooooooooongThirdArgument: number) {
}

• Open Vim/Neovim with deno lsp and lspoint's format extension enabled.
• Open both a.ts and b.ts, and make b.ts the current buffer: e a.ts, sp b.ts
• Fire lsp's formatter for a.ts: call denops#notify('lspoints', 'executeCommand', ['format', 'execute', bufnr('a.ts')]).
• No textEdit changes should be applied since a.ts but, some textEdit changes are requested by deno lsp. (These changes cannot be actually applied for a.ts, so you'll get an error message).

[denops] Error: Failed to call 'executeCommand' API in 'lspoints': Out of range: start character
[denops]     at Plugin.call (file:///Users/mityu/.cache/vim/pack/minpac/opt/denops.vim/denops/@denops-private/service.ts:260:13)
[denops]     at eventLoopTick (ext:core/01_core.js:168:7)
[denops]     at async Service.#dispatch (file:///Users/mityu/.cache/vim/pack/minpac/opt/denops.vim/denops/@denops-private/service.ts:109:12)
[denops]     at async Service.dispatch (file:///Users/mityu/.cache/vim/pack/minpac/opt/denops.vim/denops/@denops-private/service.ts:114:14)
[denops]     at async Vim.#dispatch (file:///Users/mityu/.cache/vim/pack/minpac/opt/denops.vim/denops/@denops-private/host/vim.ts:120:14)

Environment

• Vim 9.1.708
• deno 1.45.5

[mityu]

Let's wait for uga-rosa/deno-denops-lsputil#6 to be fixed 👍