### Elasticsearch Version

8.11.0

### Installed Plugins

_No response_

### Java Version

_bundled_

### OS Version

MacOS

### Problem Description

When sending a ESQL query with the `enrich` command that involves a policy that does not existing a `NullPointerException` is thrown and shown as error messages to the user:

Query:
```
row a  = 1| enrich missing-policy
```

Returns:
```
null_pointer_exception - Cannot invoke "org.elasticsearch.xpack.core.enrich.EnrichPolicy.getMatchField()" because "policy" is null
```

### Steps to Reproduce

See above.

### Logs (if relevant)

_No response_
x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/analysis/AnalyzerTests.java
var errorMsg = "Cannot use field [point] with unsupported type [geo_point]";
        verifyUnsupported("""
            from test
            | dissect point \"%{foo}\"
            """, errorMsg);
    }
    public void testUnsupportedFieldsInGrok() {
        var errorMsg = "Cannot use field [point] with unsupported type [geo_point]";
        verifyUnsupported("""
            from test
            | grok point \"%{WORD:foo}\"
            """, errorMsg);
    }
    public void testRegexOnInt() {
        for (String op : new String[] { "like", "rlike" }) {
            var e = expectThrows(VerificationException.class, () -> analyze("""
                from test
                | where emp_no COMPARISON "foo"
                """.replace("COMPARISON", op)));
            assertThat(
                e.getMessage(),
                containsString(
                    "argument of [emp_no COMPARISON \"foo\"] must be [string], found value [emp_no] type [integer]".replace(
                        "COMPARISON",
                        op
                    )
                )
            );
        }
    }