Text format to return edited ranges instead of entire document

[jefftime]

This pull request addresses the current behavior of ZLS's text formatting. Currently, ZLS will return the result of zig fmt as the replacement text for the entire range of the document. This causes odd issues in certain text editors such as Helix which lose cursor position due to the whole document being changed

This pull request adds the ability to compare the input text and the zig fmt output in order to get proper text edit ranges. I am not an expert on the LSP specification by any means, but I believe this is more in mind with how text formatting is supposed to behave. In most cases it should allow for smaller messages between the client and server as well

[leecannon]

You are going to need to rebase on master to get the CI passing.

[jefftime]

@leecannon Done

[leecannon]

Seems to work fine in vscode, I'm not setup for testing in any other editor.