proto1: update to operate over stdin

[sam-berning]

Issue #, if available:

#35

Description of changes:

Change proto1 to operate over stdin instead of over the command line.

Adds a new flag to the proto1 command, --input-file, which allows users to specify an alternate input file instead of stdin.

Also, removes the command line arguments from the subcommands of proto1.

Tested with a sample setting extension:

$ echo '{"setting-version": "v1", "value": {"name": "foo"}}' | ./target/debug/proto1-test proto1 set

$ echo '{"setting-version": "v1", "value": {"name": 1}}' | ./target/debug/proto1-test proto1 set
[2024-02-15T23:44:00Z ERROR bottlerocket_settings_sdk::model::erased] error=Failed to deserialize 'target-value' input as settings value version 'v1': invalid type: integer `1`, expected a string
    Value: {
      "name": 1
    }
[2024-02-15T23:44:00Z ERROR bottlerocket_settings_sdk::extension::proto1] error=Set operation failed: Failed to deserialize 'target-value' input as settings value version 'v1': invalid type: integer `1`, expected a string
    Value: {
      "name": 1
    }
[2024-02-15T23:44:00Z ERROR bottlerocket_settings_sdk::extension::proto1] error=Set operation failed: Failed to deserialize 'target-value' input as settings value version 'v1': invalid type: integer `1`, expected a string
    Value: {
      "name": 1
    }
Set operation failed: Failed to deserialize 'target-value' input as settings value version 'v1': invalid type: integer `1`, expected a string
Value: {
  "name": 1
}
$ echo '{"setting-version": "v1", "value": {"name": "foo"}}' > input_file.json
$ ./target/debug/proto1-test proto1 --input-file input_file.json set

$

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[jmt-lab]

I would maybe add a doc comment here just for sanity