Raise the version up to 1.5.0, add upgrade script

Fix issues found after the review

This rule executes pgindent with header files only.

Fix output precision limit for double values (issue #118)

pgSphere used its own setting (set_sphere_output_precision function)
to limit the output precision of double values, that could not be
greater than 15 significant digits (DBL_DIG). It introduced some
problems with dump/restore. PostgreSQL uses its own precision setting:
extra_float_digits. The PostgreSQL setting allows to use more significant
digits.

This patch changes the default pgSphere output behaviour to utilize
PostgreSQL extra_float_digits. Now, extra_float_digits is used by default,
until set_sphere_output_precision is called.

The old behaviour is kept for compatibility purposes. Once,
set_sphere_output_precision is called, pgSphere starts to use the old
behaviour (read, please, issue #118 discussion).

The patch introduces a new function - reset_sphere_output_precision.
It is used to reset to the PostgreSQL behaviour after using
set_sphere_output_precision.

* Update upgrade script (reset_sphere_output_precision function)

* Add test for pgSphere output precision with different settings

expected/output_precision.out   - PG 10-11
expected/output_precision_1.out - PG 12+

* Add extra_float_digits = 2 for epochprop and bounding_box_gist tests

The upgrade script misses the altering of spoint operator family
to add operator 17. It is required for k-NN search.

Change the version to 1.5.1.

Add TOK_ prefix to INT, FLOAT, SIGN token names to distinguist these
names from macro directives under mingw64.

This is so we do not invent values for pm, parallax, or rv.  We
are actually a bit over-cautious and invalidate both PMs even if
only one is missing.  This is because PMs mix, and hence there are traces
of the invented 0 in the other component of the PM.  Similarly,
when the parallax is missing or bad, the RV would be heavily contaminated;
in these cases, we copy through the original RV, as it may still be useful
and certainly will not be grossly wrong.

(sorry about a few whitespace diffs introduced by killing trailing whitespace
in sql/epochprop.sql and src/epochprop.c)

This merge request addresses issue #125 by updating the GitHub Actions CI workflow to build and test on PostrgeSQL 17.

This PR updates the version number on `actions/upload-artifact` in `.github/workflows/build-and-check.yml` in order to silence the following warning:

> The following actions use a deprecated Node.js version and will be forced to run on node20: actions/upload-artifact@v3. For more info: https://github.blog/changelog/2024-03-07-github-actions-all-actions-will-run-on-node20-instead-of-node16-by-default/

https://github.com/actions/upload-artifact says:

> actions/upload-artifact@v3 is scheduled for deprecation on November 30, 2024. [Learn more.](https://github.blog/changelog/2024-04-16-deprecation-notice-v3-of-the-artifact-actions/) Similarly, v1/v2 are scheduled for deprecation on June 30, 2024. Please update your workflow to use v4 of the artifact actions. This deprecation will not impact any existing versions of GitHub Enterprise Server being used by customers.