Upload fileName with EnvVar create/update commands

[khamilowicz]

Why

ENG-13652: Show filename when value is a file

eas env:create and eas:env:update should upload fileName, just like website.

How

• Added fileName parameter

Test Plan

Tested manually

[linear]

ENG-13653 Show file name when editing variables

[github-actions]

Size Change: -300 B (0%)

Total Size: 53 MB

Filename	Size	Change
./packages/eas-cli/dist/eas-linux-x64.tar.gz	53 MB	-300 B (0%)

_{compressed-size-action}

[codecov]

Codecov Report

Attention: Patch coverage is 50.00000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 53.05%. Comparing base (214cff0) to head (b6d7a3b).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
packages/eas-cli/src/commands/env/create.ts	0.00%	1 Missing ⚠️
packages/eas-cli/src/commands/env/update.ts	66.67%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2646      +/-   ##
==========================================
- Coverage   53.05%   53.05%   -0.00%     
==========================================
  Files         566      566              
  Lines       21615    21617       +2     
  Branches     4236     4236              
==========================================
  Hits        11466    11466              
- Misses      10119    10121       +2     
  Partials       30       30              

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[github-actions]

⏩ The changelog entry check has been skipped since the "no changelog" label is present.

[github-actions]

CodeMention:

File Patterns	Mentions
**/*	@szdziedzic, @khamilowicz, @sjchmiela