…ilter; ADBC 1.1.0 rich errors)

Conflict-free bundle of the clean commits between resolutions: VARIANT cast reading wrong rows under a filter, and the ADBC 1.1.0 Rich Error Metadata API. No conflicts with main.

`ConvertVariantToVariant` indexed the source by the raw loop counter,
ignoring the incoming selection vector, so nested `VARIANT` values were
read from the wrong rows under a filter. Map the index through
`GetMappedIndex` like the other converters.

Before:

```
❯ duckdb
-- Loading resources from /Users/mathias/.duckdbrc
DuckDB v1.5.3 (Variegata)
Enter ".help" for usage hints.
🟡◗ CREATE TABLE t AS SELECT i, MAP{'k': i::VARIANT} AS m FROM range(2) t(i);
🟡◗ SELECT m::VARIANT FROM t WHERE i = 1;
┌──────────────────────────┐
│   CAST(m AS "VARIANT")   │
│         variant          │
├──────────────────────────┤
│ [{'key': k, 'value': 0}] │
└──────────────────────────┘
🟡◗ SELECT m::VARCHAR FROM t WHERE i = 1;
┌────────────────────┐
│ CAST(m AS VARCHAR) │
│      varchar       │
├────────────────────┤
│ {k=1}              │
└────────────────────┘
```

(`'value': 0` is wrong)

After:

```
❯ ./build/release/duckdb
-- Loading resources from /Users/mathias/.duckdbrc
DuckDB v1.5.4-dev84 (Development Version, 4e6c9e9)
Enter ".help" for usage hints.
🟡◗ CREATE TABLE t AS SELECT i, MAP{'k': i::VARIANT} AS m FROM range(2) t(i);
🟡◗ SELECT m::VARIANT FROM t WHERE i = 1;
┌──────────────────────────┐
│   CAST(m AS "VARIANT")   │
│         variant          │
├──────────────────────────┤
│ [{'key': k, 'value': 1}] │
└──────────────────────────┘
🟡◗ SELECT m::VARCHAR FROM t WHERE i = 1;
┌────────────────────┐
│ CAST(m AS VARCHAR) │
│      varchar       │
├────────────────────┤
│ {k=1}              │
└────────────────────┘
```

Reported on
[Discord](https://discord.com/channels/909674491309850675/1125676736311480340/1511698549354664020)

…ilter; ADBC 1.1.0 rich errors)

Conflict-free bundle of the clean commits between resolutions: VARIANT cast reading wrong rows under a filter, and the ADBC 1.1.0 Rich Error Metadata API. No conflicts with main.

Brings these v1.5-variegata commits; they do not overlap with the main/v2.0
line, so they merge with no conflicts:

- Fix VARIANT cast reading wrong rows under a filter (duckdb#23031)
- fix(adbc): implement ADBC 1.1.0 Rich Error Metadata API (duckdb#23073)

Brings these v1.5-variegata commits; they do not overlap with the main/v2.0
line, so they merge with no conflicts:

- Fix VARIANT cast reading wrong rows under a filter (duckdb#23031)
- fix(adbc): implement ADBC 1.1.0 Rich Error Metadata API (duckdb#23073)

`ConvertVariantToVariant` indexed the source by the raw loop counter,
ignoring the incoming selection vector, so nested `VARIANT` values were
read from the wrong rows under a filter. Map the index through
`GetMappedIndex` like the other converters.

Before:

```
❯ duckdb
-- Loading resources from /Users/mathias/.duckdbrc
DuckDB v1.5.3 (Variegata)
Enter ".help" for usage hints.
🟡◗ CREATE TABLE t AS SELECT i, MAP{'k': i::VARIANT} AS m FROM range(2) t(i);
🟡◗ SELECT m::VARIANT FROM t WHERE i = 1;
┌──────────────────────────┐
│   CAST(m AS "VARIANT")   │
│         variant          │
├──────────────────────────┤
│ [{'key': k, 'value': 0}] │
└──────────────────────────┘
🟡◗ SELECT m::VARCHAR FROM t WHERE i = 1;
┌────────────────────┐
│ CAST(m AS VARCHAR) │
│      varchar       │
├────────────────────┤
│ {k=1}              │
└────────────────────┘
```

(`'value': 0` is wrong)

After:

```
❯ ./build/release/duckdb
-- Loading resources from /Users/mathias/.duckdbrc
DuckDB v1.5.4-dev84 (Development Version, 4e6c9e90a7)
Enter ".help" for usage hints.
🟡◗ CREATE TABLE t AS SELECT i, MAP{'k': i::VARIANT} AS m FROM range(2) t(i);
🟡◗ SELECT m::VARIANT FROM t WHERE i = 1;
┌──────────────────────────┐
│   CAST(m AS "VARIANT")   │
│         variant          │
├──────────────────────────┤
│ [{'key': k, 'value': 1}] │
└──────────────────────────┘
🟡◗ SELECT m::VARCHAR FROM t WHERE i = 1;
┌────────────────────┐
│ CAST(m AS VARCHAR) │
│      varchar       │
├────────────────────┤
│ {k=1}              │
└────────────────────┘
```

Reported on
[Discord](https://discord.com/channels/909674491309850675/1125676736311480340/1511698549354664020)

Upstream-Commit: duckdb/duckdb@be167b0