override: support sheet-level message data overriding for different sheets but same protoconf schema

[wenchy]

Add new metasheet option override:

// Override support sheet-level message data overriding for different sheets but same protoconf schema.
// NOTE: should be used with *scatter* option.
bool override = 19;

tableau/proto/tableau/protobuf/tableau.proto

Lines 109 to 111 in 49ea8d7

	// Scatter convert multiple workbook sheets (comma-separated) separately
	// with same schema. E.g.: Item1.xlsx,Item2.xlsx,ItemAward*.xlsx.
	repeated string scatter = 18;

// Override support sheet-level message data overriding for different sheets but same protoconf schema.
// NOTE: should be used with *scatter* option.
bool override = 19; [(tableau.field) = { name: "Override " optional: true }];

tableau/proto/tableau/protobuf/metabook.proto

Lines 60 to 65 in 49ea8d7

	// Scatter converts sheets separately with same schema.
	// each element is:
	// - a workbook name or Glob(https://pkg.go.dev/path/filepath#Glob) which is relative to this workbook: <Workbook>,
	// then the sheet name is the same as this sheet.
	// - or a workbook name which is relative to this workbook with a worksheet name: <Workbook>#<Worksheet>.
	repeated string scatter = 18 [(tableau.field) = { name: "Scatter" optional: true layout: LAYOUT_INCELL }];

[wenchy]

Maybe using yaml is a good format option. And schema checking is guaranteed for override option.