fix(ios): context-initial diacritic handling

refactor(developer): reorganize messages for adding details

refactor(developer): cleanup kmn compiler message namespaces

docs(developer): kmc-kmn api documentation and some message documentation

Merge pull request #10819 from keymanapp/chore/common/9843-keyman-touch-layout-schema-restrictive-layer-id

chore(common): loosen .keyman-touch-layout schema layer id requirements

fix(developer): make sure scroll bar appears when needed in global welcome

auto: increment beta version to 17.0.280

chore(resources): update to latest ldml: xmlns, uset

Merge branch 'refactor/developer/10207-kmn-compiler-message-namespaces' into refactor/developer/10207-message-detail

Merge branch 'docs/developer/10207-kmc-kmn-documentation' into refactor/developer/10207-kmn-compiler-message-namespaces

fix(linux): Fix libkeymancore-dev dependencies

Co-authored-by: Steven R. Loomis <srl295@gmail.com>

auto: increment beta version to 17.0.279

This change adds `libicu-dev` as a dependency for `libkeymancore-dev`.
While it is possible to dynamically build without ICU it is required
when doing a static build.

Closes #10864 and [Debian bug #1064915](
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1064915).

fix(android/engine): Check selection indexes

Co-authored-by: Joshua Horton <joshua_horton@sil.org>

chore(android/engine): Reduce toast notifications after installations

docs(linux): Updated whatsnew for Keyman for Linux 17

Co-authored-by: Darcy Wong <darcy_wong@sil.org>

Moved the ERROR_Message line above the Error_Message line for every
message in the compiler message files, as it makes the grouping clearer
once we start adding message details. For example, see the start of the
KmnCompilerMessages class.

Also wraps potentially-undefined parameters to the messages with a new
function `def`, shorthand for `CompilerMessageDef`, which converts the
parameter to '<param>' if it is undefined, which is helpful for
documentation.

Relates to #10207.

In order to include message detail in messages, it is helpful to split
out the exception messages which have a separate parameter, so that
parameter at the same position can be the message detail.

Introduces the CompilerMessageSpecWithException function which takes an
exceptionVar parameter to achieve this differentiation.

Remove Toast notifications for:
* Dictionary download is finished
* Resources successfully updated

Fixes: rename unicodeSet to uset 🙀  #10657

chore(developer): rename unicodeSet to uset 🙀  #10657

- add xmlns to schema manually

For: chore(developer): support xmlns on keyboard3 files 🙀  #10803

This is in preparation for message documentation.

Moves all messages with the KmnCompiler namespace into
KmnCompilerMessages. For now, keeps CompilerMessages class as a subclass
of KmnCompilerMessages, for removal in 18.0.

Moves messages with KmnCompiler namespace from kmw-compiler-messages.ts
to kmn-compiler-messages.ts. This avoids confusion as to source of
message, and should allow us in the future to split the classes
entirely.

- maybe last 'techpreview' update

Unblocks: chore(developer): support xmlns on keyboard3 files 🙀  #10803
Unblocks: chore(developer): rename unicodeSet to uset 🙀  #10657

For: #10803

auto: increment beta version to 17.0.278

Closes #10715.