fix(picker): wrap vim.fn.expand cword in pcall to avoid Vim:E348

[metaory]

Description

the vim.fn.expand <cword> was throwing error whenever any picker was invoked on an empty line,

The addition of this pcall would make sure that never happens.

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Fixes (Vim:E348: No string under cursor)

Error executing Lua callback: Vim:E348: No string under cursor
stack traceback:
        [C]: in function 'expand'
        ...vim/pack/plugins/opt/telescope/lua/telescope/pickers.lua:532: in function 'find'
        .../plugins/opt/telescope/lua/telescope/builtin/__files.lua:392: in function 'v'
        .../plugins/opt/telescope/lua/telescope/builtin/__files.lua:641: in function 'v'
        ...ack/plugins/opt/telescope/lua/telescope/builtin/init.lua:579: in function <...ack/plugins/opt/telescope/lua/telescope/builtin/init.lua:538>
        ...vim/pack/plugins/opt/telescope/lua/telescope/command.lua:188: in function 'run_command'
        ...vim/pack/plugins/opt/telescope/lua/telescope/command.lua:259: in function 'load_command'
        ...fig/nvim/pack/plugins/opt/telescope/plugin/telescope.lua:108: in function <...fig/nvim/pack/plugins/opt/telescope/plugin/telescope.lua:107>

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Type of change

Please delete options that are not relevant.

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

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How Has This Been Tested?

Tests

• invoking oldfiles
• invoking live_grep
• invoking other pickers that expand <cword>

Telescope Config

default telescope config with only few mapping and layout overrides

Reproduce

• issue is reproducible when invoking most pickers on an empty line

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Neovim Configuration

vanilla, using native :h packadd with ~20 packages

• Neovim version (nvim --version):

NVIM v0.10.0-dev-2451+g8b4e26915
Build type: RelWithDebInfo
LuaJIT 2.1.1707061634

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• Operating system and version:

$ hostnamectl

Static hostname: mxc
       Icon name: computer-laptop
         Chassis: laptop 💻
      Machine ID: 40fd81b10766********************
         Boot ID: e7153a5a9035********************
Operating System: Arch Linux                      
          Kernel: Linux 6.7.6-arch1-1
    Architecture: x86-64
 Hardware Vendor: Dell Inc.
  Hardware Model: XPS 13 9370
Firmware Version: 1.11.1
   Firmware Date: Thu 2019-07-11
    Firmware Age: 4y 7month 2w 6d  

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Checklist:

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

[jamestrew]

Thanks!
I can't actually get this error to trigger for me (even though I can using <C-r><C-w> in the command line for the exact same cursor position), not sure why but I think this doesn't hurt.

Just fixed the formatting.