Vits improvements

[robinhad]

vitsArgs = VitsArgs(
    # hifi V3
    resblock_type_decoder = '2',
    upsample_rates_decoder = [8,8,4],
    upsample_kernel_sizes_decoder = [16,16,8],
    upsample_initial_channel_decoder = 256,
    resblock_kernel_sizes_decoder = [3,5,7],
    resblock_dilation_sizes_decoder = [[1,2], [2,6], [3,12]],
)