fix(utils, mark picker): preserve uri in path_expand, use it in mark picker

[gzbfgjf2]

Description

Please include a summary of the change and which issue is fixed. Please also
include relevant motivation and context

Fix #3023, use the approach suggested in pull request #3024.

This commit lets mark picker preserve uri.

It firstly lets utils.path_expand() return early when input is uri, then it uses utils.path_expand() in mark picker.

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Original marked oil and fugitive buffers are opened as expected.

Configuration:

• Neovim version (nvim --version):

NVIM v0.9.5
Build type: Release
LuaJIT 2.1.1703358377

• Operating system and version:

macOS 14.4.1

Checklist:

• My code follows the style guidelines of this project (stylua)
• I have performed a self-review of my own code
• [ n/a] I have commented my code, particularly in hard-to-understand areas
• [ n/a] I have made corresponding changes to the documentation (lua annotations)

[jamestrew]

Thanks!