Use \thesis@blocks@preamble from fi.dtx for sci.dtx for now

Following commit 7510875, LaTeX2e no longer identifies packages by
pathnames, but by filenames. This breaks the inheritance mechanism
of fithesis and required copying university identifier from directory
names to LaTeX package filenames. More information is available at
https://github.com/latex3/latex2e/issues/510.

Renaming was necessary, `fithesis3.cls` has no notion of front matter.

The patch was submitted by Juraj Pálenik.

The patch was submitted by Juraj Pálenik.

The patch was submitted by Juraj Pálenik.

The patch was submitted by Juraj Pálenik.

The patch was submitted by Juraj Pálenik.

The patch was submitted by Juraj Pálenik.

The patch was submitted by Juraj Pálenik.

This conditional determines, whether the scanned assignment
specified by the `assignment` key is going to be hidden in the
digital version of the document. It is by default, but some style
files (`/mu/sci`) switch this, so that the scanned assignment is
included in the digital version.

are no longer page-numbered, so that hyperref links work correctly.

`\thesis@selectLocale` is no longer performed globally for the
entire document during `\thesis@load` (effectively overriding the
user's hyphenation settings, if Babel's or Polyglossia's
`\languagename` differs from `\thesis@locale`). Instead,
`\thesis@preamble` and `\thesis@postamble` now locally switch the
locale and expand `\thesis@blocks@preamble` and
`\thesis@blocks@postamble`, which are the new redefinables. Since
this breaks the behaviour of `\thesis@blocks@mainMatter`, whose
effects would also be local, `\thesis@blocks@mainMatter` is now
executed directly by `\thesis@preamble` after closing the group and
becomes a new part of the interface between the class and the style
files.

As a preparation for the future inclusion of bibliography support,
the /csquotes/ package is loaded, `\thesis@<locale>@csquotesStyle`
is a new part of the locale interface that sets the /csquotes/
style of a locale, and `\thesis@selectLocale` now switches the
/csquotes/ style.