feat: add @file directive

[mogery]

Summary:
Adds the @file directive, like described in #932. Uses compile_const under the hood for max code reuse and to make sure we only read a file once.

Issue Reference(s):
Fixes #932
/claim #932

Also partly addresses #764

Build & Testing:

• I ran cargo test successfully.
• I have run ./lint.sh --mode=fix to fix all linting issues raised by ./lint.sh --mode=check.

Checklist:

• I have added relevant unit & integration tests.
• I have updated the documentation accordingly.
  • feat(docs): add @file operator docs tailcallhq.github.io#100
• I have performed a self-review of my code.
• PR follows the naming convention of <type>(<optional scope>): <title>

[mogery]

This is ready now as well.

[codecov]

Codecov Report

Attention: 6 lines in your changes are missing coverage. Please review.

Comparison is base (0d300f3) 88.45% compared to head (939fc4b) 88.50%.
Report is 25 commits behind head on main.

Files	Patch %	Lines
src/blueprint/operators/file.rs	89.13%	5 Missing ⚠️
src/config/expr.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1048      +/-   ##
==========================================
+ Coverage   88.45%   88.50%   +0.04%     
==========================================
  Files         104      105       +1     
  Lines       11161    11226      +65     
==========================================
+ Hits         9873     9936      +63     
- Misses       1288     1290       +2     

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[mogery]

@meskill Do the codecov issues on this make sense? I think the testing is good enough. Not sure why the missed lines are missed.

[meskill]

@meskill Do the codecov issues on this make sense? I think the testing is good enough. Not sure why the missed lines are missed.

They do. You can check the report or annotations in the pr. It mostly about some invalid cases check and usage of file inside @expr

[mogery]

@meskill Do the codecov issues on this make sense? I think the testing is good enough. Not sure why the missed lines are missed.

They do. You can check the report or annotations in the pr. It mostly about some invalid cases check and usage of file inside @expr

ohhhhh! thanks. i didn't even think about @expr

[mogery]

Alright, added tests for expr as well.

[github-actions]

Action required: PR inactive for 2 days.
Status update or closure in 5 days.

[mogery]

Closing this PR as reworking it to use @link and @const will cause the code to be much different. @tusharmath Could you assign me to #932 and #764 as well? The new PR will solve both issues.