feat(path_display): move lnum/col next to filename for filename_first

[jamestrew]

Combines transform_devicons, transform_path and the string formatting of line and column numbers when available as create_path_display.

This offers a few benefits:

• allows moving the lnum/col values to be next to the filename rather than and the end of the rest of the path when using path_display = { 'filename_first' }. Closes Display line number with filename when using filename_first #3156
• simplifies the merging of styles when devicon hl groups are present into one function rather than split across many entry makers
• consolidates lnum/col values concatenation to one function rather than split across many entry makers so that any entry makers that support lnum/col will automatically support the disable_coordinates option that some support. closes Add disable_coordinates for buffer picker #2607
• consolidates devicon prepending for the same reasons closes Support devicons in lsp_references picker #3086

[jamestrew]

I've done some testing with some of the common pickers (find_files, live_grep, grep_string, buffers, diagnostics, lsp_[references/definition]).
I'm going to keep riding this branch for a bit.