Deprecate link_to_library(goto_functions, symbol_table, ...) [blocks: #4296]

[tautschnig]

There are no in-tree uses of this function. External users should use
link_to_library(goto_model, ...). This is in preparation of further changes that
will only support the goto_modelt-variant.

This is the more consumer-friendly variant of #4296, which works equally well until the dependencies of #4296 come into effect.

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• n/a Methods or procedures I have added are documented, following the guidelines provided in CODING_STANDARD.md.
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• Regression or unit tests are included, or existing tests cover the modified code (in this case I have detailed which ones those are in the commit message).
• n/a My commit message includes data points confirming performance improvements (if claimed).
• My PR is restricted to a single feature or bugfix.
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[allredj]

⚠️
This PR failed Diffblue compatibility checks (cbmc commit: 2a2f98c).
Build URL: https://travis-ci.com/diffblue/test-gen/builds/102689879
Status will be re-evaluated on next push.
Common spurious failures:

• the cbmc commit has disappeared in the mean time (e.g. in a force-push)

• the author is not in the list of contributors (e.g. first-time contributors).

• the compatibility was already broken by an earlier merge.