Implement UnsafeAppendBoolToBitmap for dictionary and REE builders

For more context: https://github.com/apache/arrow-go/pull/558/changes#r2758798540

This commit introduces an implementation of `UnsafeAppendBoolToBitmap()`
to `dictionaryBuilder` and `RunEndEncodedBuilder`. The current
implementation pulled from `arrow/array/builder.go` would leave the
builders in invalid states that would panic when trying to finish a
record batch.

For `dictionaryBuilder`, we defer the implementation to the inner
`indexBuilder`, which will in turn increase the logical length of the
inner buffer and set the bit.

For `RunEndEncodedBuilder` I decided to just panic after talking to
@felipecrv since the semantics of what it should do are not clear.

Author: serramatutu

arrow/array/dictionary.go

@@ -646,6 +646,12 @@ func (b *dictionaryBuilder) AppendEmptyValues(n int) {
 	}
 }
 
+func (b *dictionaryBuilder) UnsafeAppendBoolToBitmap(v bool) {
+	b.length += 1
+	b.nulls += 1
+	b.idxBuilder.UnsafeAppendBoolToBitmap(v)
+}
+
 func (b *dictionaryBuilder) Reserve(n int) {
 	b.idxBuilder.Reserve(n)
 }

arrow/array/encoded.go

@@ -398,6 +398,10 @@ func (b *RunEndEncodedBuilder) AppendNulls(n int) {
 	}
 }
 
+func (b *RunEndEncodedBuilder) UnsafeAppendBoolToBitmap(v bool) {
+	panic("Calling UnsafeAppendBoolToBitmap on a run-end encoded array is logically unsound.")
+}
+
 func (b *RunEndEncodedBuilder) NullN() int {
 	return UnknownNullCount
 }