feat(cdk/table): add optional footer to cdk-text-column/mat-text-column

Added two new inputs to CdkTextColumn:
`footerText` (string) and `footerTextTransform` (function), automatically
inherited by MatTextColumn.

If the table does not define a footer, the column footer will be ignored.

Additionally, TextColumnOptions includes a new default function called
`defaultFooterTextTransform`, used when neither `footerTextTransform` nor
`footerText` are provided.

Fixes #24532

tools/public_api_guard/cdk/table.md

@@ -414,6 +414,7 @@ export class CdkTextColumn<T> implements OnDestroy, OnInit {
     dataAccessor: (data: T, name: string) => string;
     headerCell: CdkHeaderCellDef;
     headerText: string;
+    footerText: string;
     footerTextTransform: (name: string) => string;
     justify: 'start' | 'end' | 'center';
     get name(): string;