add specializations svd_trunc(!) for TruncatedAlgorithm (#171)

* add specializations `svd_trunc(!)` for `TruncatedAlgorithm`

* update changelog

* add specializations `eig_trunc(!)` for `TruncatedAlgorithm`

* pullback truncation error warning

* remove letblocks

Author: lkdvos

docs/src/changelog.md

@@ -24,6 +24,8 @@ When releasing a new version, move the "Unreleased" changes to a new version sec
 
 ### Changed
 
+- The Mooncake rules for truncated decompositions with `TruncatedAlgorithm` now use the pullbacks that make use of the full decomposition. ([#171](https://github.com/QuantumKitHub/MatrixAlgebraKit.jl/pull/171))
+
 ### Deprecated
 
 ### Removed