CODEC-315: Fix possible IndexOutOfBoundException thrown by PhoneticEngine.encode method

[arthurscchan]

This fixes possible StringIndexOutOfBoundsException and ArrayIndexOutOfBoundsException in src/main/java/org/apache/commons/codec/language/bm/PhoneticEngine.java thrown by PhoneticEngine.encode() when the provided string only contains one of the name prefix of the chosen NameType or only contain single quotation character.

This PR fixes the parameter for the split method and adds a conditional check to ensure only strings and arrays are not empty before processing.

We found this bug using fuzzing by way of OSS-Fuzz. It is reported at https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=64376 and https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=64395.

[garydgregory]

@arthurscchan
Thank you for your PR.
Please see my comments.

[garydgregory]

@arthurscchan
Please use a better description in PRs and JIRA: Specify the class and method where the exception occurs.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 50.00000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 92.27%. Comparing base (44e4c4d) to head (ee02460).
⚠️ Report is 656 commits behind head on master.

Files with missing lines	Patch %	Lines
...ache/commons/codec/language/bm/PhoneticEngine.java	50.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##             master     #223   +/-   ##
=========================================
  Coverage     92.27%   92.27%           
- Complexity     1742     1743    +1     
=========================================
  Files            67       67           
  Lines          4584     4585    +1     
  Branches        709      710    +1     
=========================================
+ Hits           4230     4231    +1     
  Misses          242      242           
  Partials        112      112           

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