Support some more string encodings; UTF-8 in particular

[chris-allan]

Follow on from #196 and support some more string encodings. Also when a particular encoding is chosen (ISO-8859-1 in particular), use it rather than always encoding in UTF-8. I am assuming this was the intent for the TILEDB_STRING_ASCII type but let me know whether pure US-ASCII was actually intended. This should make TileDB-Java compatible with all the string encodings that are currently possible via TileDB-Py.

/cc @kkoz, @erindiel

[gsvic]

Thank you for the contribution @chris-allan! The PR looks good, the only concern is that we should preferably use the ISO_8859_1 encoding in both TILEDB_STRING_ASCII and TILEDB_CHAR as both are intended to be ASCII and use the UTF_8 encoding only in TILEDB_UTF8 data type. + @Shelnutt2

[chris-allan]

No problem. Just let me know what you decide and I can make that change. Since I think everything is UTF-8 encoded on the Python side there's really not a precedent set for the ASCII encodings there.

[gsvic]

No problem. Just let me know what you decide and I can make that change. Since I think everything is UTF-8 encoded on the Python side there's really not a precedent set for the ASCII encodings there.

Hi @chris-allan. If you could just make a change for handling TILEDB_CHAR and TILEDB_STRING_ASCII the same way (ISO_8859_1) it would be great. This is the only change needed.

[gsvic]

LGTM!

[chris-allan]

@Shelnutt2 / @gsvic: Anything else you would like done here?

[gsvic]

@Shelnutt2 / @gsvic: Anything else you would like done here?

Merged!