Add support for the following two extensions: [Zvfh](https://github.com/riscv/riscv-v-spec/blob/master/v-spec.adoc#185-zvfh-vector-extension-for-half-precision-floating-point): Vector Extension for Half-Precision Floating-Point [Zvfhmin](https://github.com/riscv/riscv-v-spec/blob/master/v-spec.adoc#184-zvfhmin-vector-extension-for-minimal-half-precision-floating-point): Vector Extension for Minimal Half-Precision Floating-Point For instructions (`vfncvt[.rtz].x[u].f.w`) and (`vfwcvt.f.x[u].v`) which will become defined when `SEW = 8`, a new template `VectorFloatWideningAndNarrowingCvtDecodeBlock` is added and 8-bit floating point type (`float8_t`) is defined. The data type `float8_t` is introduced in the newer `3e` version of the SoftFloat Package, however, the current version in use is `3d` which does not include this definition. Despite this, `float8_t` is utilized solely for constructing the `vfncvt[.rtz].x[u].f.w` and `vfwcvt.f.x[u].v` instructions when `SEW = 8`. There are no operations that directly manipulate data of the `float8_t` type.