fix(one-app-server-bundler): serve-module read and write the module map once

[PixnBits]

Description

Read and write the module map from/to disk O(1) rather than O(n) in serve-module.

Motivation

Filesystem operations are slower than memory operations, so with #622 it'll be useful to reduce the total filesystem operations from 2*number of modules to just 2.

Should help reduce startup time with one-app-runner (albeit not as extreme as #622).

Test Conditions

existing tests pass 🙌
added a test to verify the thrown exception message when no modules are provided

Types of changes

Check boxes that apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation (adding or updating documentation)
• Dependency update
• Security update

Checklist

Check boxes that apply:

• My code follows the code style of this project.
• My change requires a change to the documentation and I have updated the documentation accordingly.
• These changes should be applied to a maintenance branch.
• I have added the Apache 2.0 license header to any new files created.

[10xLaCroixDrinker]

@PixnBits you've got a failing snapshot

[10xLaCroixDrinker]

@PixnBits I believe either perf or refactor would be the correct commit type, not fix.