Frozen indices are deprecated which makes all the [SQL features supporting frozen indices](https://www.elastic.co/guide/en/elasticsearch/reference/current/sql-index-frozen.html) obsolete.

This includes:

* `index_include_frozen` request parameter in the `_sql` endpoint
* `index.include.frozen` (J|O)DBC driver settings
* `SHOW TABLES INCLUDE FROZEN` queries and the `FROZEN INDEX` kind in the corresponding response
* The `FROZEN` modifier in `FROM` clauses (as in `SELECT * FROM FROZEN archive`)

`_search` raises a deprecation warning when frozen indices are being searched with `ignore_throttled=false`. SQL could do the same when the `index_include_frozen` request parameter is set or when the `FROZEN` keyword is used.

Relates to https://github.com/elastic/elasticsearch/issues/70192
x-pack/plugin/sql/src/main/java/org/elasticsearch/xpack/sql/parser/CommandBuilder.java
case SqlBaseLexer.OPTIMIZED -> Explain.Type.OPTIMIZED;
                case SqlBaseLexer.MAPPED -> Explain.Type.MAPPED;
                case SqlBaseLexer.EXECUTABLE -> Explain.Type.EXECUTABLE;
                default -> Explain.Type.ALL;
            };
        }
        boolean graphViz = ctx.format != null && ctx.format.getType() == SqlBaseLexer.GRAPHVIZ;
        Explain.Format format = graphViz ? Explain.Format.GRAPHVIZ : Explain.Format.TEXT;
        boolean verify = (ctx.verify == null || Booleans.parseBoolean(ctx.verify.getText().toLowerCase(Locale.ROOT), true));
        return new Explain(source, plan(ctx.statement()), type, format, verify);
    }
    @Override
    public Object visitShowFunctions(ShowFunctionsContext ctx) {
        return new ShowFunctions(source(ctx), visitLikePattern(ctx.likePattern()));
    }
    @Override
    public Object visitShowTables(ShowTablesContext ctx) {
        TableIdentifier ti = visitTableIdentifier(ctx.tableIdent);
        String index = ti != null ? ti.qualifiedIndex() : null;
        return new ShowTables(
            source(ctx),
            visitLikePattern(ctx.clusterLike),
            visitString(ctx.cluster),
            index,
            visitLikePattern(ctx.tableLike),
            ctx.FROZEN() != null
        );
    }
    @Override
    public Object visitShowSchemas(ShowSchemasContext ctx) {