Page.open() / Page.setLocation() functionality added

[Lozadaa]

fix issue #4869

---

This change is 

[CLAassistant]

Thank you for your submission, we really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.

---

Richard Lozada seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[heruan]

@Lozadaa please stop creating the same PR over and over: just open a single one, sign the CLA and wait for a Vaadin member to give you feedback.

[Lozadaa]

@Lozadaa please stop creating the same PR over and over: just open a single one, sign the CLA and wait for a Vaadin member to give you feedback.

@heruan Sorry, i'll open this PR. Thx for you reply.

[Lozadaa]

Reopen PR fixing sonarqube issues

[vaadin-bot]

SonarQube analysis reported 3 issues

Note: The following issues were found on lines that were not modified in the pull request. Because these issues can't be reported as line comments, they are summarized here:

1. Page.java#L74: Call "Optional#isPresent()" before accessing the value.
2. Page.java#L88: Call "Optional#isPresent()" before accessing the value.
3. Page.java#L426: Define and throw a dedicated exception instead of using a generic one.

[Lozadaa]

commits still waiting for CLA but i was sign license.

[heruan]

@Lozadaa, pay attention to what the CLA assistant is telling you:

Richard Lozada seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.

You committed using rlozada@bbr.cl but your GitHub e-mail address is richardalozada@hotmail.com so the commits might not be yours; add rlozada@bbr.cl to your GitHub profile or commit again as richardalozada@hotmail.com.