Deprecated Base64Utils causing warning

[pmpurifoy]

Steps for repro:
-run gradlew compileJava
-view warning
D:\POSSUM\src\main\java\com\target\devicemanager\components\printer\PrinterDevice.java:278: warning: [removal] Base64Utils in org.springframework.util has been deprecated and marked for removal
Base64Utils.decodeFromString(content.data),
^
Note: Some input files use unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
1 warning

Docs mention warning using Base64Utils: https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/util/Base64Utils.html

Fix:
Use java.util.Base64
https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/Base64.Decoder.html#decode(java.lang.String)

From:
Base64Utils.decodeFromString(content.data)

src\main\java\com\target\devicemanager\components\printer\PrinterDevice.java line 278

To:
Base64.getDecoder().decode(content.data)

I verified this fixes the issue locally, but no write access so I can't publish PR.

[rrenkor]

This issue has been resolved with PR #14.
Thank you @pmpurifoy for the issue finding and resolution!