hui:link-possible-types - Fix ilink creation to HyWiki and Org bufs

[rswgnu]

• hui:link-possible-types - Fix ilink creation to HyWiki and Org bufs
  hui:link-possible-types - For Org/Org-Roam ids, send 2nd arg of current heading
  string to 'link-to-org-id' call.
  hui:link-possible-types - If in a HyWiki page but not on a heading line, use a
  'link-to-wikiword' with the page name and line number.
  hui:link-possible-types - For HyWiki links, wrap a call of 'hpath:org-normalize-title'
  around 'hywiki-org-format-heading' to ensure everything but the title is removed.

• org-id, org-id:help - Fix to remove "id:" prefix so that uuid check predicates
  succeed properly.

• hpath:suffixes - Add ".org" suffix to expand HyWiki page references that have
  only instance, line, or column references and are handled by
  'pathname-line-and-column'.

• ibut:insert-text - For 'actypes::link-to-org-id', change from a double-quoted
  link to a double square bracketed Org link. This allows including the title
  from the Org heading linked to which is stored in the current Hyperbole button
  attribute, 'lbl-key'.

• hywiki-org-get-heading-match-regexp - Handle both HyWiki dir custom todo
  keywords when in a page and Org standard todo keywords, otherwise.

• pathname-line-and-column, hib-link-to-file-line - Expand HyWiki page name using
  'hywiki-get-page-file' before try to expand in current directory.

• hpath:at-p, hpath:find-line - Handle pathname expansion of HyWiki page names.

• hpath:call - (file-exists-p "") returns t, so fix to check for empty string
  before calling that.

• hpath:normalize - Handle directory paths and avoid reading in the
  file to handle it.

• hpath:validate - Fix to strip #suffix before validation and add it back
  on return.

• hywiki-existing-word - Simplify pathname check without calling other ibtypes.

• hpath:suffixes - Remove ".org" as it triggers pathname ibtype when it
  shouldn't and overrides `hywiki-existing-word'.
  hywiki-word-regexp - Add optional .org suffix so "WikiWord.org#section"
  works.

• hywiki-add-org-id - Remove (hmouse-choose-link-and-referent-windows)
  as this is not what inserts a link but just creates the wikiword referent.

• hywiki-referent-menu - Change from inserting a string link to an Org link
  that includes the associated Org heading title. Change format from "ID: uuid"
  to [[id:uuid][title]].

• hui:link-possible-types - Update id handling in all of these.

• hpath:is-p - Unless 'non-exist' arg is sent or path is a remote file, return
  path only if it exists.

• hsys-org-uuid-is-p - Add and use in "hibtypes.el" and "hui.el".

• link-to-org-id - Add optional heading 'title' arg for use in 'hbut:insert-text'
  where ibut links are created.

• hsys-org-link-at-p - Don't shrink label region down to just the description
  part of the Org link, leave it as the entire space inside the Org open and
  close brackets. This makes link activation work better.

• hibtypes.el (action): Ensure if action name is bound only as a variable
  that there are no arguments within the angle brackets. If there are,
  then it is not an action button.

• hywiki-tests--save-referent-org-id - Fix to mock 'org-id-get' instead of
  'org-id-get-create' and add call to `hywiki-get-referent' to ensure
  referent is created and read back properly.

• hywiki-get-page-file - The page file may have previously been resolved and
  sent as input here. If it exists, simply use it.

• hpath:is-p - Remove 'file-exists-p' call because 'hpath:normalize' handles
  that while accounting for path #suffixes which the 'file-exists-p'
  call mistakenly nullifies.

• hpath:validate - Fix so if a file named "myfile#name", validate
  accepts it without treating the #name as a suffic/section to be stripped.
  Fix that 'suffix' was set to the whole path string when suffix-start' was
  null. Now it is set properly to nil.