`CompletionItem` always defaults to being a `Snippet`

[kdheepak]

The specification allows InsertTextFormat to be plain text or a snippet.

/**
 * Defines whether the insert text in a completion item should be interpreted as
 * plain text or a snippet.
 */
export namespace InsertTextFormat {
	/**
	 * The primary text to be inserted is treated as a plain string.
	 */
	export const PlainText = 1;

	/**
	 * The primary text to be inserted is treated as a snippet.
	 *
	 * A snippet can define tab stops and placeholders with `$1`, `$2`
	 * and `${3:foo}`. `$0` defines the final tab stop, it defaults to
	 * the end of the snippet. Placeholders with equal identifiers are linked,
	 * that is typing in one will update others too.
	 */
	export const Snippet = 2;
}

Currently in LanguageServer.jl, creating an instance of CompletionItem always defaults to being a Snippet.

https://github.com/julia-vscode/LanguageServer.jl/blob/f9edb8091b067fc296170333a67a037af20387c4/src/protocol/completion.jl#L106

The 11th argument is hardcoded as 2.

https://github.com/julia-vscode/LanguageServer.jl/blob/f9edb8091b067fc296170333a67a037af20387c4/src/protocol/completion.jl#L99

Can LanguageServer.jl be updated to use PlainText by default and use Snippet explicitly whenever required?

[kdheepak]

There's also a client snippet support capability that is probably related to this discussion:

https://github.com/microsoft/language-server-protocol/blob/de8e4859fd9a8065486d268fc3562fd5a4813fee/_specifications/specification-3-15.md#L3125