[Enhancement] KCL builtin file system package

[zong-zhe]

Feature Request

Is your feature request related to a problem? Please describe:

There are no methods for interacting with the file system in KCL's builtin functions.

Describe the feature you'd like:

Provides a set of predefined methods for interacting with the file system

Describe alternatives you've considered:

The Filesystem Functions in Terraform: https://developer.hashicorp.com/terraform/language/functions/abspath
The Filesystem Functions in Helm: https://helm.sh/docs/chart_template_guide/accessing_files/

Teachability, Documentation, Adoption, Migration Strategy:

The methods to be implemented are listed here, in descending order of priority from top to bottom

Some basic functions:

• file.read(filepath): Read the file contents from the file path. feat: add build-in method 'file.read' to load file #1034
• file.workdir(): Gets the workdir .feat: add builtin io function workdir() #1054
• file.modpath(): Gets the module path ( KCL package root or a single KCL file path ). feat: add builtin io function modpath() #1056
• glob(pattern): Search for all paths that match pattern feat: add builtin io function glob() #1051
• file.abs(): Convert a relative path to an absolute path. feat: add file.exsits and file.abs functions #1157
• file.exists(filepath): Check whether the file path exists. feat: add file.exsits and file.abs functions #1157

Some advanced functions:

Bug fix:

• Missing type check for filesystem functions
• • fix: add type check for builtin filesystem function #1052

Docs:

• feat: add docs for filesystem builtin functions kcl-lang.io#288