MySqlDecimal does not support `ZEROFILL` column

[bgrainger]

Software versions
MySqlConnector version: 2.2.7
Server type (MySQL, MariaDB, Aurora, etc.) and version: MySQL 8.0
.NET version: 7.0

Describe the bug

MySqlDataReader.GetMySqlDecimal can't read a value from a column with the ZEROFILL attribute.

Exception

FormatException: Could not parse the value as a MySqlDecimal: 0000000000.0000000000
   at MySqlConnector.MySqlDecimal..ctor(String value) in C:\Code\MySql\MySqlConnector\src\MySqlConnector\MySqlDecimal.cs:line 46
   at MySqlConnector.Core.Row.GetMySqlDecimal(Int32 ordinal) in C:\Code\MySql\MySqlConnector\src\MySqlConnector\Core\Row.cs:line 415
   at MySqlConnector.MySqlDataReader.GetMySqlDecimal(Int32 ordinal) in C:\Code\MySql\MySqlConnector\src\MySqlConnector\MySqlDataReader.cs:line 276
   at UserQuery.Main(), line 33

Code sample

drop table if exists dectest;
create table dectest(value decimal(20,10) zerofill);
insert into dectest(value) values(0),(1),(0.1);

using var cmd = new MySqlCommand("select value from dectest", connection);
using var reader = cmd.ExecuteReader();
while (reader.Read())
    reader.GetMySqlDecimal(0).Dump();

Expected behavior

Reads the column value as a MySqlDecimal.

Additional context

Reported here: #1075 (comment)

[alexr17]

If you wanted to parse these zerofilled decimals using .NET primitives and truncate it, that's possible, but from testing we could only support precision up to about 29/30 digits.

[bgrainger]

That's why the MySqlDecimal type exists: to store MySQL DECIMAL values that fall outside the range of a System.Decimal.