but the user requests it

Ref: #1807

The implications of this are large for using eSpeak-ng as a phonemizer. It means that it's now possible to get accurate mappings between the phonemized word and the original word (up till now it was pretty much impossible). This is huge for many applications that use it as a side-tool.

This reverts commit 56a4c82d99.

`#if PLATFORM_WINDOWS` doesn't work for some reason.

Fix suggested by @beqabeqa473

So that SelectVoice can select an mbrola language.

Fixes #1011

Otherwise we won't ever be able to select an mbrola voice in ssml
processing.

We should initialize current_voice_id so that ssml processing knows what
voice we currently have, and not try to change it unless really needed.

When e.g. using mbrola voices, the sample rate may change. When the
application plays audio itself, it needs to know it, and
espeak_ng_GetSampleRate does not report that.

this fix was lost in commit 84e967c0a, I can’t even imagine how it happened.
thank God it’s not me who was merging it.

The correction uses substitute character (0x001A) as a workaround. This
control character is the "older brother" of the replacement character
OxFFFD.

The workaround is necessary because the replacement character (0xFFFD)
is used to flag to indicate an error or EOF. The substitute character
(0x001A) was included as an alternative flag to indicate that the input
character itself is a replacement character (0xFFFD).

Signed-off-by: Alan Coopersmith <[email protected]>

Co-authored-by: adr-adr <adr@github>

https://github.com/espeak-ng/espeak-ng/issues/1972

Co-authored-by: Baybars Külebi <[email protected]>
Co-authored-by: gullabi <[email protected]>
Co-authored-by: mllopartbsc <[email protected]>

On non-FHS systems like NixOS, there is no `/usr`. Additionally,
Nix has immutable packages so mbrola cannot be installed to espeak-ng’s
`datadir`. Instead, packages are expected to find data under one of the paths
listed in `XDG_DATA_DIRS` environment variable, as defined in the XDG Base
Directory Specification:
https://specifications.freedesktop.org/basedir-spec/basedir-spec-0.6.html#variables